Favorite topics for users

For registered users, we would like to have the ability to "Favorite" libraries, tags and subject areas. To accomplish this will require additional building on both the front and back end, and can be broken up like this:

1. DB update for the users/contributors to support favorites for each of the three areas.

2. for libraries, adding a "Heart" that can be clicked, and save it for that user. Same for the individual library page.

3. Those libraries should also be at the top of the page on the page load, so the page load should sort by that.

4. The tags currently only work as a filter on the card view. we could have the heart icon appear when being actively filtered, and that could show in the dropdown later when selected.

5. we need to be able to invite users with favorites by email on the back end regarding their favorite items to participate in reviews or other community relevant activities.

6. As part of a new "Areas" sections that will focus on Boost's relation to specific topics of interest, we should allow users to "favorite" those areas as well