It is possible that cleanup will be executed
right after repair-based node operations,
in which case we have a 5 minutes timer
before off-strategy compaction is started.
After marking the sstables that need cleanup,
perform offstrategy compaction, if needed.
This will implicitly cleanup those sstables
as part of offstrategy compaction, before
they are even passed for view update (if the table
has views/secondary index).
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>