Add filters to course activity section

[acelaya]

Depends on https://github.com/hypothesis/lms/pull/6466

Continuing with the work from https://github.com/hypothesis/lms/pull/6453, this PR adds filters to the course section.

The main difference here is that the courses dropdown starts with the "active" course (the one represented in the URL) pre-selected. Then, selecting a different course does not apply a filter to the activity table, as we are implicitly filtering by a single course. Instead, once a different course is selected, we navigate to that course and propagate the rest of the filters there.

To do/discuss

• [ ] The courses dropdown behavior which "navigates" instead of "filter", presents a few cases that we need to discuss.
  • What to do when "All courses" is selected. We could navigate to the home page in that case.
  • What to do when the active course is clicked. The default multi-select behavior would be to de-select that course, which in this case is the same as selecting "all courses", so perhaps we could also navigate to the home page.
• [x] Selects manage references to objects in order to determine what options are selected. In this case we are passing a course object which deep-equals one from the list, but is a different reference, so it is not marked as selected. We could:
  • ~Refactor Select component to do deep-equal checks in order to determine if an option is selected.~
  • Slightly change the local logic so that we handle a list of IDs instead of a list of objects, which would require separately tracking the corresponding names. -> We are doing this as part of https://github.com/hypothesis/lms/pull/6466
• [x] Implement logic to initialize filters based on query parameters, so that we can navigate to other places and propagate filters. -> Being implemented in https://github.com/hypothesis/lms/pull/6466
• [ ] Add tests.

[acelaya]

Conflicts got a bit complex. Closing and recreating in new branch