Access Cleaned Links from other tabs/windows

There’s a number of annoying websites that still use popups, where the addon buttons are not available. If a whitelist error happens there it is hard to correct so we should find a way to do that.

No files, tests, or entry points are named. Start by locating the whitelist error handling and the communication between addon controls and other tabs or windows; done should mean that cleaned links remain accessible there and whitelist errors can be corrected even on popup-based websites.

Written by the indexing model from the issue text.