[WIP] Improve external storage configuration UI

This PR will track several changes to the external storages UI. When complete, fixes #7737, fixes #7738 and fixes #8174.

First change is the highlighting of fields that are not optional and are not filled.
Ideally we shouldn't use `.parent().parent()` but `.closest('selector_for_the_element_we_are_looking_for')` but I understand that you probably copied the bad code from above.