Remove replaced_by_txid from wallet code

Summary:
Remove replaced_by_txid from wallet code

Fixes T112

Test Plan: make check && test/functional/test_runner.py --extended

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: jasonbcox, teamcity

Maniphest Tasks: T112

Differential Revision: https://reviews.bitcoinabc.org/D1036