Use library spinner when typing or switching tags

[paulkaplan]

We now appropriately show a spinner when libraries appear, but typing into the filter or switching tags is still very slow. We should use the spinner effectively to prevent a crunchy experience.

Tag clicking should act just like the initial load: show the spinner and then start the render. This is because that render could be just as long as the initial library load, so has the same potential for making the buttons feel locked.

Typing is a bit touchier, I think we should use a "debounce" strategy:

• When you start typing, show the loader so we do not try to render the library while you are typing.
• Start a timer to start rendering the library, something like 500ms.
• If you get more change events during that 500ms, cancel the timer and restart it.

This will allow you to type fluidly without getting interrupted by a library re-render.