Redeprecates the `/_xpack/rollup` endpoints in favor of `/_rollup`.
When we cleanup the rollup in a cluster containing 6.x nodes we need to
use `/_xpack/rollup` instead of `/_rollup` because the 6.x nodes don't
know about `/_rollup`. In those cases we must ignore the deprecation
warnings that the 7.0 node will return for the end point.
Closes#36044
This adds a `wait_for_completion` flag which allows the user to block
the Stop API until the task has actually moved to a stopped state,
instead of returning immediately. If the flag is set, a `timeout` parameter
can be specified to determine how long (at max) to block the API
call. If unspecified, the timeout is 30s.
If the timeout is exceeded before the job moves to STOPPED, a
timeout exception is thrown. Note: this is just signifying that the API
call itself timed out. The job will remain in STOPPING and evenutally
flip over to STOPPED in the background.
If the user asks the API to block, we move over the the generic
threadpool so that we don't hold up a networking thread.
lcawl
Nik Everett
Zachary Tong
Jason Tedor
Zachary Tong