Temporary course sandbox to store courses that have not been assigned a term

[BrandonLim8890]

A feature we can add is the ability for users to add classes into a "sandbox" type area in the sidebar to keep classes that users are thinking about taking, but have not yet decided where in their schedule to take it. Just some initial ideas, this will probably just be an area for users to add courses to, and drag courses in to. Won't be used for prereqs and coreqs

Basically, we just want a way to better utilise the sidebar when users haven't selected a major.