feat: add library favorites

[CK-7vn]

Description of the change

This feature adds the ability for users to favorite libraries. A user clicks the star icon in the right hand corner of the LibraryCard component located in the Libraries tab of Open Content, and that Library is added to the library_favorites table. This also opens up two endpoints in handlers/open_content.go, GET /api/open-content/favorites and PUT /api/open-content/{id}/save. The GET requests returns a users favorites in the order of most recently favorited. The PUT handler checks the database and either adds a favorite row in the library_favorites table for that library and that user, and or soft-deletes the favorite from the library_favorites table if an entry for that user, and that library is already present. The favorites tab combined Video favorites and Library favorites into one cumulative page so that a user can view all of their open content favorites.

• Related issues: closes Allow Residents to Favorite Libraries #493

Screenshot(s)

Additional context

A couple unrelated changes were changing the videos favoriting icon from a bookmark to a star, and also adding an explicit favorite route for videos because the prior implementation checked an {action} which required admin privileges with the new feature flagging, this made it impossible for users to favorite a video, so that was changed and added as well.

[CK-7vn]

ALSO
I fixed the routing when an Admin switches from student view back to admin view while on the favorites page.

[CK-7vn]

Couple more things I need to figure out, just involving moving the Unfavoriting to the Favorites Card. I'm tapping out tonight. Sorry. I'll make sure its done tomorrow. ASAP.

[CK-7vn]

Ok Ok @calisio <- I switched the unfavoriting into the card, sorry, it should have been that way in the first place. The payload is necessary because of the way that the unfavoriting works on the backend...but I did switch change as much as I could...the bug with the Admin switching back to student view was fixed, double checked and the favorites are still being returned to you in order of most recently favorited, but that handler did change slightly to add the pagination.

[calisio]

I think besides those comments, everything else is looking good (as long as @PThorpe92 thinks the backend looks good!)

[PThorpe92]

backend looks good 👍

[CK-7vn]

Sweeet! I just force pushed those updates @calisio