[feature]: add list of script key types to querier

[guggero]

Now that we have a way to specify a slice of values in a WHERE ... IN (...) SQL query (#1621) we should address the following TODO:

taproot-assets/taprpc/taprootassets.proto

Line 1248 in c9b71df

// TODO(guggero): Add a bit field that allows querying for multiple

The mention of "bit field" here is probably misleading, as cramming things into a single integer isn't easy to understand or implement. So a simple "slice of script key types to select for" is probably better as a description of the TODO.

The idea is that the user can specify exactly what combination of script keys types they want to query for, resulting in a list of script key types that are then used in the different queries that support the ScriptKeyTypeQuery gRPC request type (ListAssets, ListUtxos, ListBalances and maybe more).