TODO: Psbt add methods to access Tx info

[junderw]

Could be getters:
inputs: hash, index, sequence
outputs: script, value

New method:
CheckForPubkey = pass it an index and a pubkey, it will take the hash160 and decompile the scriptPubkey, redeemScript (if any) and witnessScript (if any) to search for the pubkey or its hash160 and return true or false if it finds it. This method should also be available for outputs as well. Should throw an error if it sees a P2SH/P2WSH without the corresponding script.

[junderw]

Solved in #1561 and #1563