Prototype-based selectors and predicates

[0x009922]

Current implementation

In the current design, the predicates and selectors are constructed directly, as all other data model types:

const accounts: types.Account[] = await client.find
  .accounts({
    predicate: types.CompoundPredicate.Atom(
      types.AccountProjectionPredicate.Id.Domain.Name.Atom.EndsWith('land')
    )
  })
  .executeAll()

 const items: [types.Hash, types.AccountId][] = await client.find
   .transactions({
     selector: [
       types.CommittedTransactionProjectionSelector.BlockHash.Atom,
       types.CommittedTransactionProjectionSelector.Value.Authority.Atom,
     ],
   })
   .executeAll()

This is somewhat unintuitive and verbose, and is different from how these work in Rust:

TODO: a snippet in Rust with QueryBuilder

Desired solution

The desired way is to adopt a similarly-looking strategy from Rust, i.e. by using callbacks with "prototypes" of the entities, as if we are actually accessing fields on the final structures:

const accounts: types.Account[] = await client.find
  .accounts({
    filterWith: (account) => account.id.domain.name.endsWith('land')
  })
  .executeAll()

const items: [types.Hash, types.AccountId][] = await client.find
 .transactions({
   selectWith: (tx) => [tx.blockHash, tx.value.authority],
 })
 .executeAll()