Add loading state to flyout.

Upon clicking the recommendations link the flyout immediately opens
and displays a spinner until completion of api request.

Change-Id: Idf091a98e108e577cbc57563c8f8540964b2bfef
Simplify loading CSS

Change-Id: Ia30e7ed55b41abcedb6a1e82a3eaa08bb952414a
Merge "Add loading state to flyout."
Merge "Simplify loading CSS"