Revisit and add new RPC methods

[bibajz]

I do not recall which version of Bitcoin Core was the last released version of this library tested against.

With Bitcoin Core v24.1 being released few days ago - https://github.com/bitcoin/bitcoin/releases/tag/v24.1 - and v25.0 possible being released in few weeks, it's worth taking a look on:

• what was changed
• what was added
• what was removed

#15 should help with testing this.

As for the additional RPC methods, of particular interest are those related to PSBTs, so take a look at them.