Move other search over to new markup

[JessRudder]

In order to add multiple filters for the classroom page (to enable filtering by whether or not a class was archived), I had to create separate search/filtering code (the existing code was very reliant on there only being one filter option and we now needed two).

The initial plan was to leave both sets of search/filter in place side by side until there was a reason to move the old code over. I discovered that the existing search (visible on assignment and group assignment pages) is only partially functional so it seemed like the right time to fix and unify the code.

This PR:

• Switches assignment/group assignment views to use new search/filter markup
• Gets assignment/group assignment filter/search to use same JS as the classroom index
• Fixes filtering bug when someone chooses Created at:
• Fixes bug in new search implementation that was preventing debouncing from happening
• Moves markup into reusable partials (maybe...we'll see if this makes sense once things are in place)