walletdb: don't automatically salvage when corruption is detected

Summary:
Partial (4/11) backport of core PR18918:
https://github.com/bitcoin/bitcoin/pull/18918/commits/8ebcbc85c652665b78dcfd2ad55fa67cafd42c73

Depends on D8590.

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, majcosta

Reviewed By: #bitcoin_abc, majcosta

Differential Revision: https://reviews.bitcoinabc.org/D8591