Re-instate the auto target repository swap, however prevent any alert from being displayed if the target branch can't be automatically changed. In this instance, we're essentially assuming that a user is using the new UI of Bitbuckets Create Pull Request

Remove automatic selection of target repository.
Bitbucket's recent UI update has seemingly fixed this bug themselves, so there is no longer a need for this extension to do it

Update placement of code Copy button to be inset within the code itself, rather than appending to the end. This prevents layout jank as the paragraph extends (when the button is shown) and shrinks (when the button is hidden)