StorageGRID detects "Cassandra repair progress slow" alert due to NOT_STARTED repair

• StorageGRID detects "Cassandra repair progress slow" alert
• The effectiveRepairPercent is not increasing, it may sometimes decrease
• Support > Metrics > Cassandra Network Overview shows Reaper Repaired Percentage of storagegrid decreases
• reaper_commands.txt in StorageGRID log(on any storage node) or command results of "spreaper list-runs"(executed by root) shows that reaper runs triggered for storagegrid keyspace gets into NOT_STARTED state

Example:

    "creation_time": "2021-11-03T22:52:54Z",
    "current_time": "2021-12-06T08:24:55Z",
    "datacenters": [],
    "duration": null,
    "end_time": null,
    "estimated_time_of_arrival": null,
    "id": "c7af6780-3cf8-11ec-805b-09184f94412d",
    "incremental_repair": false,
    "intensity": 1.000,
    "keyspace_name": "storagegrid",
    "last_event": "no events",
    "nodes": [],
    "owner": "storagegrid",
    "pause_time": null,
    "repair_parallelism": "PARALLEL",
    "repair_thread_count": 4,
    "repair_unit_id": "95eddf80-224e-11eb-82a1-5fcc54d415e5",
    "segments_repaired": 0,
    "start_time": null,
    "state": "NOT_STARTED",
    "total_segments": 24218