Add UI flow for adding files by case ID

[agduncan94]

This is similar to the add file by file ID/name, however, the search input is the case ID. A table will be created showing all of the files available from that case. Clicking on a file will grab metadata from the GDC API and display it. The user can then click the add track button.

Note that the second portion of this is very similar to the by file id/name. We could make it more generic so that we can reuse code between the two UIs (use inheritance).