Adopt diff-friendly import style. (#4173)

## Summary

This PR adjusts our `stylish-haskell` configuration to always import
each symbol on a separate line. Example:
```hs
import Some.Module.A
    ( SomeSymbolA1
    , SomeSymbolA2
    )
import Some.Module.B
    ( SomeSymbolB1
    , SomeSymbolB2
    , SomeSymbolB3
    , SomeSymbolB4
    )
````

## Details

This change has several advantages:
1. **Better cross-version compatibility**: this configuration produces
[almost exactly the
same](731127c)
output across versions `0.11.0.3` and `0.14.5.0` of `stylish-haskell`
(current and latest versions respectively).
1. **Better cross-tool compatibility**: the output is almost identical
to that produced by **`fourmolu`**. (See experimental `fourmolu` branch
[here](https://github.com/cardano-foundation/cardano-wallet/pull/4061/files).)
1. **Improved diff-friendliness**: we virtually eliminate the problem
where adding or removing a single import can lead to a multi-line diff.

Adopting this style will make it easier to move to GHC `9.2` or `9.6`,
both of which no longer work with our current version of
`stylish-haskell`.

## Related Issues

Without this change in our configuration, upgrading `stylish-haskell`
from version `0.11.0.3` to `0.14.5.0` exposes us to the following
regression:
haskell/stylish-haskell#462

.stylish-haskell.yaml

@@ -4,7 +4,7 @@
 # https://github.com/jaspervdj/stylish-haskell/blob/master/data/stylish-haskell.yaml
 # for usage.
 
-columns: 80 # Should match .editorconfig
+columns: 1 # Force diff-friendly import style (one line per symbol).
 steps:
   - imports:
       align: none

lib/address-derivation-discovery/lib/Cardano/Byron/Codec/Cbor.hs

@@ -44,39 +44,62 @@ module Cardano.Byron.Codec.Cbor
 import Prelude
 
 import Cardano.Address.Derivation
-    ( XPub, xpubToBytes )
+    ( XPub
+    , xpubToBytes
+    )
 import Cardano.Wallet.Address.Derivation
-    ( Depth (..), DerivationType (..), Index (..) )
+    ( Depth (..)
+    , DerivationType (..)
+    , Index (..)
+    )
 import Cardano.Wallet.Primitive.Passphrase
-    ( Passphrase (..) )
+    ( Passphrase (..)
+    )
 import Cardano.Wallet.Primitive.Types.Address
-    ( Address (..) )
+    ( Address (..)
+    )
 import Cardano.Wallet.Primitive.Types.Hash
-    ( Hash (..) )
+    ( Hash (..)
+    )
 import Cardano.Wallet.Primitive.Types.ProtocolMagic
-    ( ProtocolMagic (..) )
+    ( ProtocolMagic (..)
+    )
 import Cardano.Wallet.Primitive.Types.Tx
-    ( unsafeCoinToTxOutCoinValue )
+    ( unsafeCoinToTxOutCoinValue
+    )
 import Cardano.Wallet.Primitive.Types.Tx.TxIn
-    ( TxIn (..) )
+    ( TxIn (..)
+    )
 import Cardano.Wallet.Primitive.Types.Tx.TxOut
-    ( TxOut (..) )
+    ( TxOut (..)
+    )
 import Control.Monad
-    ( replicateM, when )
+    ( replicateM
+    , when
+    )
 import Crypto.Error
-    ( CryptoError (..), CryptoFailable (..) )
+    ( CryptoError (..)
+    , CryptoFailable (..)
+    )
 import Crypto.Hash
-    ( hash )
+    ( hash
+    )
 import Crypto.Hash.Algorithms
-    ( Blake2b_224, SHA3_256 )
+    ( Blake2b_224
+    , SHA3_256
+    )
 import Data.ByteString
-    ( ByteString )
+    ( ByteString
+    )
 import Data.Digest.CRC32
-    ( crc32 )
+    ( crc32
+    )
 import Data.Either.Extra
-    ( eitherToMaybe )
+    ( eitherToMaybe
+    )
 import Data.Word
-    ( Word8 )
+    ( Word8
+    )
 
 import qualified Cardano.Wallet.Primitive.Types.Coin as Coin
 import qualified Cardano.Wallet.Primitive.Types.TokenBundle as TokenBundle

lib/address-derivation-discovery/lib/Cardano/Wallet/Address/Book.hs

@@ -37,19 +37,29 @@ import Cardano.Wallet.Address.Derivation
 import Cardano.Wallet.Address.Derivation.Shared
     ()
 import Cardano.Wallet.Address.Derivation.SharedKey
-    ( SharedKey (..) )
+    ( SharedKey (..)
+    )
 import Cardano.Wallet.Primitive.Types.Address
-    ( Address, AddressState (..) )
+    ( Address
+    , AddressState (..)
+    )
 import Control.Lens
-    ( Iso', iso, withIso )
+    ( Iso'
+    , iso
+    , withIso
+    )
 import Data.Kind
-    ( Type )
+    ( Type
+    )
 import Data.Map.Strict
-    ( Map )
+    ( Map
+    )
 import Data.Type.Equality
-    ( type (==) )
+    ( type (==)
+    )
 import Fmt
-    ( Buildable (..) )
+    ( Buildable (..)
+    )
 
 import qualified Cardano.Wallet.Address.Discovery.Random as Rnd
 import qualified Cardano.Wallet.Address.Discovery.Sequential as Seq

lib/address-derivation-discovery/lib/Cardano/Wallet/Address/Derivation.hs

@@ -80,47 +80,74 @@ module Cardano.Wallet.Address.Derivation
 import Prelude
 
 import Cardano.Address.Derivation
-    ( XPrv, XPub )
+    ( XPrv
+    , XPub
+    )
 import Cardano.Mnemonic
-    ( SomeMnemonic )
+    ( SomeMnemonic
+    )
 import Cardano.Wallet.Primitive.NetworkId
-    ( HasSNetworkId (..), SNetworkId )
+    ( HasSNetworkId (..)
+    , SNetworkId
+    )
 import Cardano.Wallet.Primitive.Passphrase.Types
-    ( Passphrase (..) )
+    ( Passphrase (..)
+    )
 import Cardano.Wallet.Primitive.Types.Address
-    ( Address (..) )
+    ( Address (..)
+    )
 import Cardano.Wallet.Primitive.Types.RewardAccount
-    ( RewardAccount (..) )
+    ( RewardAccount (..)
+    )
 import Control.Applicative
-    ( (<|>) )
+    ( (<|>)
+    )
 import Control.DeepSeq
-    ( NFData )
+    ( NFData
+    )
 import Control.Monad
-    ( (>=>) )
+    ( (>=>)
+    )
 import Data.Bifunctor
-    ( first )
+    ( first
+    )
 import Data.Bits
-    ( (.&.) )
+    ( (.&.)
+    )
 import Data.ByteArray
-    ( ByteArray, ByteArrayAccess )
+    ( ByteArray
+    , ByteArrayAccess
+    )
 import Data.ByteArray.Encoding
-    ( Base (..), convertFromBase, convertToBase )
+    ( Base (..)
+    , convertFromBase
+    , convertToBase
+    )
 import Data.ByteString
-    ( ByteString )
+    ( ByteString
+    )
 import Data.Kind
-    ( Type )
+    ( Type
+    )
 import Data.List.NonEmpty
-    ( NonEmpty (..) )
+    ( NonEmpty (..)
+    )
 import Data.Maybe
-    ( fromMaybe )
+    ( fromMaybe
+    )
 import Data.Proxy
-    ( Proxy (..) )
+    ( Proxy (..)
+    )
 import Data.Scientific
-    ( Scientific, toBoundedInteger )
+    ( Scientific
+    , toBoundedInteger
+    )
 import Data.String
-    ( fromString )
+    ( fromString
+    )
 import Data.Text
-    ( Text )
+    ( Text
+    )
 import Data.Text.Class
     ( CaseStyle (..)
     , FromText (..)
@@ -130,23 +157,36 @@ import Data.Text.Class
     , toTextFromBoundedEnum
     )
 import Data.Type.Equality
-    ( (:~:) (..), testEquality )
+    ( (:~:) (..)
+    , testEquality
+    )
 import Data.Word
-    ( Word32, Word8 )
+    ( Word32
+    , Word8
+    )
 import Fmt
-    ( Buildable (..) )
+    ( Buildable (..)
+    )
 import GHC.Generics
-    ( Generic )
+    ( Generic
+    )
 import GHC.Stack
-    ( HasCallStack )
+    ( HasCallStack
+    )
 import GHC.TypeLits
-    ( Symbol )
+    ( Symbol
+    )
 import Quiet
-    ( Quiet (..) )
+    ( Quiet (..)
+    )
 import Safe
-    ( readMay, toEnumMay )
+    ( readMay
+    , toEnumMay
+    )
 import Type.Reflection
-    ( Typeable, typeRep )
+    ( Typeable
+    , typeRep
+    )
 
 import qualified Data.ByteString as BS
 import qualified Data.Text as T

lib/address-derivation-discovery/lib/Cardano/Wallet/Address/Derivation/Byron.hs

@@ -56,7 +56,10 @@ import Cardano.Crypto.Wallet
     , unXPub
     )
 import Cardano.Mnemonic
-    ( SomeMnemonic (..), entropyToBytes, mnemonicToEntropy )
+    ( SomeMnemonic (..)
+    , entropyToBytes
+    , mnemonicToEntropy
+    )
 import Cardano.Wallet.Address.Derivation
     ( Depth (..)
     , DerivationType (..)
@@ -67,31 +70,45 @@ import Cardano.Wallet.Address.Derivation
     , PaymentAddress (..)
     )
 import Cardano.Wallet.Primitive.NetworkId
-    ( SNetworkId (..) )
+    ( SNetworkId (..)
+    )
 import Cardano.Wallet.Primitive.Passphrase
-    ( Passphrase (..) )
+    ( Passphrase (..)
+    )
 import Cardano.Wallet.Primitive.Types.Address
-    ( Address (..) )
+    ( Address (..)
+    )
 import Cardano.Wallet.Primitive.Types.ProtocolMagic
-    ( magicSNetworkId )
+    ( magicSNetworkId
+    )
 import Control.DeepSeq
-    ( NFData )
+    ( NFData
+    )
 import Control.Lens
-    ( Lens, lens )
+    ( Lens
+    , lens
+    )
 import Crypto.Hash.Algorithms
-    ( SHA512 (..) )
+    ( SHA512 (..)
+    )
 import Crypto.Hash.Extra
-    ( blake2b256 )
+    ( blake2b256
+    )
 import Data.ByteArray
-    ( ScrubbedBytes )
+    ( ScrubbedBytes
+    )
 import Data.ByteString
-    ( ByteString )
+    ( ByteString
+    )
 import Data.Kind
-    ( Type )
+    ( Type
+    )
 import Data.Proxy
-    ( Proxy (..) )
+    ( Proxy (..)
+    )
 import GHC.Generics
-    ( Generic )
+    ( Generic
+    )
 
 import qualified Cardano.Byron.Codec.Cbor as CBOR
 import qualified Cardano.Wallet.Address.Derivation as W