Improve How Rescope Works for Large Instances with Tens of Thousands of Open Pull Requests

The rescoping process for large instances with a large number of open pull requests, tens of thousands, Bitbucket can take longer to update open pull requests when there's a change because of the ways rescope traverses all open pull requests, and would also throw the Pull request merges fail since "New changes were pushed" error while trying to merge pull requests that have just been pushed to.

For scenarios like these, Bitbucket should have an option to run a rescope limiting it to the project in which the push has happened or even to the repository, to allow for a better pull request update performance.