540729ef4b Implement analyzepsbt RPC and tests (Andrew Chow)
77542cf2a5 Move PSBT UTXO fetching to a separate method (Andrew Chow)
cb40b3abd4 Figure out what is missing during signing (Andrew Chow)
08f749c914 Implement joinpsbts RPC and tests (Andrew Chow)
7344a7b998 Implement utxoupdatepsbt RPC and tests (Andrew Chow)
Pull request description:
This PR adds 3 new utility RPCs for interacting with PSBTs.
`utxoupdatepsbt` updates a PSBT with UTXO information from the node. It only works with witness UTXOs because full transactions (as would be needed for non-witness UTXOs) are not available unless txindex is enabled.
`joinpsbts` joins the inputs from multiple distinct PSBTs into one PSBT. e.g. if PSBT 1 has inputs 1 and 2, and PSBT 2 has inputs 3 and 4, `joinpsbts` would create a new PSBT with inputs 1, 2, 3, and 4.
`analyzepsbt` analyzes a PSBT and determines the current state of it and all of its inputs, and the next step that needs to be done.
Tree-SHA512: 3c1fa302201abca76a8901d0c2be7b4ccbce334d989533c215f8b3e50e22f2f018ce6209544b26789f58f5980a253c0655111e1e20d47d5656e0414c64891a5c