util: add TransactionError includes and namespace declarations

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.

src/interfaces/wallet.h

@@ -35,6 +35,9 @@ struct bilingual_str;
 namespace common {
 enum class PSBTError;
 } // namespace common
+namespace node {
+enum class TransactionError;
+} // namespace node
 namespace wallet {
 class CCoinControl;
 class CWallet;