6b8d86ddb8 Require a public key to be retrieved when signing a P2PKH input (Andrew Chow)
Pull request description:
If we do not have the public key for a P2PKH input, we should not continue to attempt to sign for it.
This fixes a problem where a PSBT with a P2PKH output would include invalid BIP 32 derivation paths that are missing the public key.
Tree-SHA512: 850d5e74c06833da937d5bf0348bd134180be7167b6f9b9cecbf09f75e3543fbad60d0abbc0b9afdfa51ce165aa36168849f24a7c5abf1e75f37ce8f9a13d127
Added functional tests for PSBT that test the RPCs. Also added all
of the BIP 174 test vectors (except for the updater tests) in the
functional tests.
Added a Unit test for the BIP 174 updater test vector.