CLC-1701 - Badges - Show a message when there are no items in the pop-over

https://jira.media.berkeley.edu/jira/browse/CLC-1701

Also fixes the following:

* Spacing next to users name
* Remove duplicate border-radius
* Add border beneath badge title
* Make clickable area way bigger - accessible + touch
* Remove `display:inline`, `vertical-align`
* Make the designs more uniform (same line-height)