`stop job` won't kill the job process in local mode

`stop job` in yarn mode will call `killYarnJob` to stop job. But in local mode or yarn-client mode, it'll only modify the job info table. So the job process will still be running.

https://github.com/4paradigm/OpenMLDB/blob/14a734c2a6f06acd137947eca875074dec3ec61f/java/openmldb-taskmanager/src/main/scala/com/_4paradigm/openmldb/taskmanager/JobInfoManager.scala#L106-L115

- [x] doc
- [ ] a better way, support stop job in local or yarn-client mode?

The issue points to JobInfoManager.scala lines 106-115. Examine the stopJob method to see how it handles local and yarn-client modes versus yarn mode. Look for where job processes are spawned and managed in these modes to understand how to send a kill signal. Testing will involve running a job in local mode and attempting to stop it.

Written by the indexing model from the issue text.