Trigger a webhook from a pull request with a button

One of the missing features that is stopping our users from switching to the native Bitbucket Server webhooks is the ability to trigger a webhook from a pull request via a button. An example would be a button displayed at the top of a pull request page that tells a CI system to now build the pull request.

This feature was part of the now discontinued Pull Request Notifier plugin which has been de-listed from the marketplace. https://github.com/tomasbjerre/pull-request-notifier-for-bitbucket