During garbagecollect use index check for tombstone removals

nodetool garbagecollect command may be further improved to actually remove more tombstones. Right now bloom filter is used and may give false positives preventing tombstone removal if min table timestamp is less than tombstone timestamp.

Disabling bloom filter should do the trick, but currently there is a bug in compaction with bloom filter turned off CASSANDRA-14944

As improvement index can be always checked if garbagecollect compaction is done