Avoid double compaction by cleaning partition files in 2 cycles

[anna-tran]

What this PR does
Updates the blocks cleaner to clean completed partition groups in 2 cycles instead of 1.
In the first cycle of the cleaner,

1. mark parent blocks of completed partition groups as deleted
2. update the bucket index to add the new result blocks and remove deleted blocks

Even if another compactor sees a stale version of the bucket index from step 1, it won't create a new partition group because the partition group file still exists.

In the second cycle of the cleaner,

1. delete the existing partition group info

Which issue(s) this PR fixes:
Fixes #7129

Checklist

• Tests updated
• Documentation added
• CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX]

[danielblando]

Thanks

[alexqyle]

LGTM

[yeya24]

LGTM