submit job compact can be stopped

[Sophie-Xie]

Describe the background of the requirement

• user want to stop the compaction job

Describe the detail of the requirement

• just provide a stop command to stop the compaction job

Describe the scenarios of the requirement

• the compaction job run a long time and didn't know when it will stop or the compaction affect the performance

from @dbacyj

[critical27]

Rocksdb does provide an interface to stop it, it has an CancelAllBackgroundWork, but it is used when shutting down.
If we use it as a stop or cancel, upcoming compact will return error like below, even if the server is not shutting down.

W20220726 16:00:06.155649 1525392 RocksEngine.cpp:499] CompactAll Failed: Shutdown in progress: Database shutdown