Since commit 3dc9a81d02 (repair: Repair
table by table internally), a table is always repaired one after
another. This means a table will be repaired in a continuous manner.
Unlike before a table will be repaired again after other tables have
finished the same range.
```
for range in ranges
for table in tables
repair(range, table)
```
The wait interval can be large so we can not utilize the assumption if
there is no repair traffic, the whole table is finished.
After commit 3dc9a81d02, we can utilize
the fact that a table is repaired continuously property and trigger off
strategy automatically when no repair traffic for a table is present.
This is especially useful for decommission operation with multiple
tables. Currently, we only notify the peer node the decommission is done
and ask the peer to trigger off strategy compaction. With this
patch, the peer node will trigger automatically after a table is
finished, reducing the number of temporary sstables on disk.
Refs #10462Closes#10761
e0aca10bcd