In this commit, we update the SignDescriptor struct to instead use the
keychain.KeyDescriptor struct inplace of a raw public key. We do this
as this allows for a recovery mode, where the caller doesn’t know what
key was used exactly, but remembers the precise KeyDescriptor. A
stateless signer is still able to re-derive the proper key, as it’s
given the full path.
In this commit, we rename several of the existing WitnessType
definitions to be more descriptive than they were previously. We also
add a number of additional types which we need to handle scripts for,
but weren’t yet added before. Finally, we modify the
receiverHtlcSpendTimeout to optionally take an additional parameter to
set the locktime of the spending transaction accordingly. This final
modification allows the caller to specify that the lock time has
already been set on the main transaction.
