core: use loop.Keystore, support arbitrarily prefixed Cosmos addresses

[cfal]

BCI-1740

• adds a loop.Keystore implementation using keystore.Cosmos and uses it; note that this is still for unprefixed keys, such that key management using the key controller follows existing conventions (ie. manage a single Cosmos keystore key used across Cosmos chains)
• adds a cosmostxm.KeystoreAdapter that translates loop.Keystore accounts into prefixed Cosmos addresses
• updates cosmostxm.KeyWrapper to wrap a KeystoreAdapter instance for a specific prefixed Cosmos address

[github-actions]

I see that you haven't updated any README files. Would it make sense to do so?

[cfal]

working on fixing the SigScanner check..

[krehermann]

looks good to me upto the question about a mutex.

out of curiousity - how burdensome was it to understand what to write? i'm excited that you could figure it out and i'm wondering if we could have made it easier to understand. based on the code, i'm guessing that starknet was a good example

[cfal]

thanks for the quick reviews! waiting on the fix for the sigscanner check :)

out of curiousity - how burdensome was it to understand what to write? i'm excited that you could figure it out and i'm wondering if we could have made it easier to understand. based on the code, i'm guessing that starknet was a good example

it wasn't too bad, i spent most of the time thinking on what Sign() should be doing since there's only a single []byte param, and since the common tx signing function in cosmos-sdk requires other metadata params: https://github.com/cosmos/cosmos-sdk/blob/3e07c80ebc5913e20c87cc34b881afe42e94b2bd/client/tx/tx.go#L166

making it as basic as possible (priv key signing a blob, instead of tx-scoped) seemed to work out, and even if the loop.Keystore cound be bech32-prefix-aware and support other metadata fields when signing, it would have required other changes (eg. what should Accounts() return?)

there's still the question of how chain operators would know the addresses on different chains, since the key controller/operator ui/keystore.Cosmos only shows a non-prefixed pubkey, but i think we can address that at a later point.

[calvwang9]

whats the reasoning behind empty pubkey vs panicking?

[cfal]

the reasoning was that we don't want the node/process to crash - for example, if account was mistyped. addresses can be specified via TOML for transmitter address, although i didn't bother to trace the code path to see if user input could actually end up here.

[cl-sonarqube-production]

SonarQube Quality Gate

69.4% Coverage on New Code (is less than 80%)

See analysis details on SonarQube

[augustbleeds]

^ keeping the branch restored so it can be used for tests on chainlink-cosmos