That's intended to fix a bad layer violation as table was given the
responsibility of disabling compaction for a given table T, but that
logic clearly belongs to compaction_manager instead.
Additionally, gate will be used instead of counter, as former provides
manager with a way to synchronize with functions running under
run_with_compaction_disabled. so remove() can wait for their
termination.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>