Add a workflow transition so the peer reviewer can move from IR back to dev

Example:

https://tracker.moodle.org/browse/MDL-73727

1) I peer reviewed this (and was too hasty) and push it to IR

2) it failed CI so I'd like to take it back out of IR

3) but I have no capability to do this even though I'm the peer reviewer on the tracker. I could steal it and assign to myself and workflow it and assign back to Kevin but that feels a bit janky

It would make sense for the reporter to also have the same power, in the case when something was implemented which didn't hit the mark.