pgsql: pg_resetwal: Add more tests and test coverage

pg_resetwal: Add more tests and test coverage

pg_resetwal had poor test coverage. There are some TAP tests, but
they all run with -n, so they don't actually test the full
functionality. (There is a non-dry-run call of pg_resetwal in the
recovery test suite, but that is incidental.)

This adds a bunch of more tests to test all the different options and
scenarios.

Reviewed-by: Aleksander Alekseev <aleksander(at)timescale(dot)com>
Discussion: https://www.postgresql.org/message-id/flat/0f3ab4a1-ae80-56e8-3426-6b4a02507687(at)eisentraut(dot)org

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7b5275eec3a50d55f5750357b8a223cf5f0bb59f

Modified Files
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src/bin/pg_resetwal/t/001_basic.pl | 204 +++++++++++++++++++++++++++++++++
src/bin/pg_resetwal/t/002_corrupted.pl | 8 ++
2 files changed, 212 insertions(+)