### What changes were proposed in this pull request?
Adding support for `removeWorkersUnavailabeInfo`, `getDecommissioningWorkers` and `runIsDecommissioning`. This was missed in the last PR.
### Why are the changes needed?
see above
### Does this PR introduce _any_ user-facing change?
no
### How was this patch tested?
added unit tests
Closes#2735 from akpatnam25/CELEBORN-1593.
Authored-by: Aravind Patnam <akpatnam25@gmail.com>
Signed-off-by: mingji <fengmingxiao.fmx@alibaba-inc.com>
### What changes were proposed in this pull request?
`master --send-worker-event` should support `RECOMMISSION` and `NONE` event type.
### Why are the changes needed?
Legal event types of `/api/v1/workers/events` are `IMMEDIATELY`, `DECOMMISSION`, `DECOMMISSION_THEN_IDLE`, `GRACEFUL`, `RECOMMISSION`, `NONE`. Therefore, `master --send-worker-event` should also support `RECOMMISSION` and `NONE` event type.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
`TestCelebornCliCommands#master --send-worker-event`
Closes#2734 from SteNicholas/CELEBORN-1572.
Authored-by: SteNicholas <programgeek@163.com>
Signed-off-by: mingji <fengmingxiao.fmx@alibaba-inc.com>
### What changes were proposed in this pull request?
Introducing the Celeborn CLI (based on this [CPIP](https://cwiki.apache.org/confluence/display/CELEBORN/CIP-7+Celeborn+CLI)). For the first iteration, adding support for querying the existing REST api endpoints.
After this will add a layer for external cluster manager support. Further improvements are needed such as pretty print, which can be added in subsequent PRs.
### Why are the changes needed?
see [CPIP](https://cwiki.apache.org/confluence/display/CELEBORN/CIP-7+Celeborn+CLI)
### Does this PR introduce _any_ user-facing change?
yes, new CLI tool.
### How was this patch tested?
added UTs and also tested internally.
Closes#2699 from akpatnam25/cli-CELEBORN-1572.
Lead-authored-by: Aravind Patnam <apatnam@linkedin.com>
Co-authored-by: Aravind Patnam <akpatnam25@gmail.com>
Signed-off-by: Mridul Muralidharan <mridul<at>gmail.com>
