Add command to unapprove then reapprove an already approved PR

[eric-blue]

I wasn't sure where to report this issue since the bot repo is private

Due to a config option on github, we are constantly getting stuck with coderabbit already approving the PR, but after a force push github is expecting it to "re-approve" the PR.

Propose adding a command to @coderabbitai reapprove or to adjust the @coderabbitai full review command to handle this edge-case

[linear]

ENG-1096 Add command to unapprove then reapprove an already approved PR