[Improvement] Adopt proto-ts client methods

[jrwbabylonlab]

1. In babylon-proto-ts/src/lib/rpc, there are two files: baby.ts and btc.ts, each containing a set of RPC client methods.
   2. Update simple-staking to adopt and replace its current methods with the ones from this library — especially for the BTC staking part (BABY staking is already using the library methods).
   3. If you find any methods in simple-staking that don’t yet exist in the library, add them to the library as well.

The file you’ll want to review in simple-staking is useBbnQuery.ts.