Handle not-the-inbox-views nicer

Currently if you move to archived etc it will say you have loads of unreads. need to ignore those views and maybe update the dock so you know you're not looking at the inbox

Start by reproducing the unread count while viewing archived and other non-inbox views, then inspect the TypeScript userscript entry point responsible for the dock count. Done means those views no longer contribute to the inbox unread total and the dock makes the current non-inbox view clear.

Written by the indexing model from the issue text.