Prevent disappearance of user details after using ULS

There was an issue with using ULS: when selecting a language
into which nobody translates and then clearing the filter,
the usernames would not appear.

This is fixed by adding the 'pane' class when emptying
elements with the 'details' class and renaming the other
element with 'details' class to 'request-info'.

Tests included.

Change-Id: Iff87c7db07ab4f3a86b8fff4fd7d2b2f8e28f980
Merge "Prevent disappearance of user details after using ULS"