Add ckecli rq reset-backoff command

[yokaze]

What

When reboot-queue is stuck, normally we do some manual operation and wait for the next reboot.
The waiting time can be shortened if we can reset the backoff of a reboot entry.

How

Implement ckecli rq reset-backoff to reset the backoff count and time

Checklist

• Finish implentation of the issue
• Test all functions
• Have enough logs to trace activities
• Notify developers of necessary actions