Move BerkeleyEnvironment::Salvage into BerkeleyBatch::Recover
Summary:
Partial backport (6/11) of core PR18918:
https://github.com/bitcoin/bitcoin/pull/18918/commits/ced95d0e43389fe62b5d30fcc7c42dbca0e88242
Depends on D8592.
Test Plan:
ninja all check-all
Reviewers: #bitcoin_abc, majcosta
Reviewed By: #bitcoin_abc, majcosta
Differential Revision: https://reviews.bitcoinabc.org/D8593