Summary:
The patch adds compaction filter support for wide-column entities by introducing
a new `CompactionFilter` API called `FilterV3`. This API is called for regular
key-values, merge operands, and wide-column entities as well. It is passed the
existing value/operand or wide-column structure and it can update the value or
columns or keep/delete/etc. the key-value as usual. For compatibility, the default
implementation of `FilterV3` keeps all wide-column entities and falls back to calling
`FilterV2` for plain old key-values and merge operands.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/11196
Test Plan: `make check`
Reviewed By: akankshamahajan15
Differential Revision: D43094147
Pulled By: ltamasi
fbshipit-source-id: 75acabe9a35254f7f404ba6173ee9c2774382ebd