[FEATURE] Add input/dropdown to [courseid]

[awpala]

Is your feature request related to a problem? Please describe.
Improve functionality of the page / workflow through the site.

Describe the solution you'd like
Add single select drop-down (or equivalent MUI component, ideally with inline search/drilldown feature) to [courseid] so the course can be selected from the same page. If landing on it initially from index (home page), selector is pre-selected with the course already.

N.B. Can either update the query param dynamically, or if that's too cumbersome/tricky to implement, just pull the relevant data off of allCourseData passed in as a prop instead, along with courseId (in fact, we can use this too in general to avoid passing in redundant data for the course, since course can be reconstituted already via allCourseData[courseId] at the top-level scope of the function body if following this latter approach).

Describe alternatives you've considered
(N/A)

Additional context
(N/A)

[awpala]

NOTE: Let's NOT do this before auth & review form, but a good near-term MVP/MVP+ feature if we can swing it...