Implement SQLiteDatabase::TxnBegin, TxnCommit, and TxnAbort

Summary:
This is a backport of core#19077 [14/26]
https://github.com/bitcoin/bitcoin/pull/19077/commits/010e3659069e6f97dd7b24483f50ed71042b84b0

Depends on D10561

Test Plan:
With clang-tidy:
ninja

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D10562