All cell versions should not be retained during flushes and minor compaction when maxlookback is disabled

HBase allows coprocessors to override the column family data retention properties dynamically within coprocessor hooks for flushes and compactions.

The Phoenix TTL feature overrides the data retention properties such that all cells including delete markers are preserved and then the decision of what to be removed is determined in its compaction scanner called CompactionScanner. However, doing this when max lookback is disabled leads to retaining all row versions during minor compaction and flushes unnecessarily.