webadmin: Fix height of EntityModelWidgetWithInfo

Fixed the height to be the same as most other widgets, to correct all
sorts of layout issues. Also removed references to styles that no
longer exist.

Change-Id: Ia3a8381cf747609389f6c2ec806bef65d9248ee1
Bug-Url: https://bugzilla.redhat.com/1115524
Signed-off-by: Lior Vernia <lvernia@redhat.com>