Pluggable compression algorithms

[rafael]

Feature Description

We want to enable users to plug different compression algorithms into the backups infrastructure. Important context for this issue:

• pgzip was changed to pargzip, this introduced a significant regression in performance. Because of this, we reverted that change in release 9.0 branch Revert "backup: Use pargzip instead of pgzip for compression." #8174
• There is already a PR in progress to support pluggable compression algorithms. In that PR we will make pgzip the default, but pargzip will also be supported. You can follow the progress of that work in: Support for additional compressors/decompressors #7978
• Depending on user needs, once Support for additional compressors/decompressors #7978 lands, we will check whether or not to backport this change to Vitess release 9.0 or 10.0.

Use Case(s)

Users could have different requirements/needs that influences which algorithm makes more sense in their environment (e.g., optimizing for size, cpu, or memory).