fix: Ensure document level mousedown listener is last

[ConradJChan]

Issue

With the logic added to BaseAnnotator to setActiveId to null when mousedown event is encountered this introduced a regression where if you click on the same annotation a second time, the annotation would no longer become active

Solution

Due to the way React handles events, an event listener added to document before the React code mounts will always be invoked first. The approach here is to attach the event listener to document after the React code mounts, or more accurately, after the React code that matters mounts, i.e. *List components that have mousedown logic, in order to take advantage of being able to prevent event propagation when appropriate.

TODO:

• unit tests
• cross browser testing

[jstoffan]

Do we need a whole manager for this or can we follow the HighlightListener convention?

[ConradJChan]

I tried to go with the HighlightListener convention first, but it kind of needs the BaseManager logic of inserting a div to mount the react component so I ended up duplicating most of the BaseManager