Add TransactionError to node namespace and include it directly instead of
relying on indirect include through common/messages.h
This is a followup to a previous commit which moved the TransactionError enum.
These changes were done in a separate followup just to keep the previous commit
more minimal and easy to review.
Add separate PSBTError enum instead of reusing TransactionError enum for PSBT
operations, and drop unused error codes. The error codes returned by PSBT
operations and transaction broadcast functions mostly do not overlap, so using
an unified enum makes it harder to call any of these functions and know which
errors actually need to be handled.
Define PSBTError in the common library because PSBT functionality is
implemented in the common library and used by both the node (for rawtransaction
RPCs) and the wallet.
New node/types.h file is analagous to existing wallet/types.h and is a better
place to define simple node types that are shared externally with wallet and
gui code than the util library.
Motivation for this change is to completely remove util/error.h file currently
holding TransactionError in a followup commit.