webadmin: Created class hierarchy for bond popups

Created a class hierarchy for bond popup windows to replace the "compact
mode" boolean parameter mechanism. This to enable better control over
which windows enable creating new bonds from the engine in following
patches.

Change-Id: Ib9f4de41a5d298bf922e9ad7fee64ee2b62c3700
Signed-off-by: Lior Vernia <lvernia@redhat.com>