Reset segment might leave segment in disabled state if the controller fails to re-enable it

In `PinotHelixResourceManager`, `resetSegment()` and `resetAllSegments()` will temporarily disable the partition if the partition state is not `ERROR`, then re-enable it after it becomes `OFFLINE`. If controller fails to re-enable the partition (restarted, encounters exception when waiting for segment to become `OFFLINE` etc.), the partition will be left disabled.

To fix it, we should use the same mechanism as Helix - send a state transition message to the instance to bring it to OFFLINE state.