Label page list redesign: Add outer border

Problem to solve

With Label list page redesign with draggable labels we added a new design for our Labels page. During a separate design discussion we decided to add a border outline for the gray background when using the new card design.

In the current Labels page UI, this detail is missing right now. See https://gitlab.com/gitlab-org/gitlab-ce/labels for an example.

Proposal

Add border outline according to specs outline in the linked comment.

Two details to consider:

• We are showing headers here
• Paging footer is inside the gray background box currently. This should be corrected to only have the content boxed. Pagination is outside.