Remove PR approvals only when the diff changes

Currently there is the feature to remove PR approvals when the source branch changes. We love that to make sure there aren't big changes after the approvals that then get merged in without actually being reviewed. This feature is starting to be more of a hinderance when people are just trying to sync up their feature branches or resolve conflicts.

This feature would change the default behavior or add a new option which removes the approvals when the code diff changes, or perhaps with a percentage change limit. This fixes an inconvenience where the PR gets approvals, then the branch is synced with the target and the reviewers have to look through the code again when there isn't actually anything new to review.