Implement RBF in Spectrum

[moneymanolis]

The current error is:
cryptoadvance.spectrum.spectrum.RPCError: ('Method not found (utxoupdatepsbt)', -32601)

since the RPC call utxoupdatepsbt doesn't exist / isn't handled in Spectrum.

BDK could be used here.

More background in this issue:
cryptoadvance/specter-desktop#2173