Add Search and Category side panels

This patch adds two right side floating panels.
By default panels are hidden and only small
right side toggle buttons are visible. When user
click the side button a corresponding panel
will show up.
Right now this only UI part CSS\html part
is covered. There should be a handler for them
in django code.

Also fix issues with images. URL now point to
correct image handler.

Partially implements: blueprint app-catalog-ui
Change-Id: Ia8e4b06bf7f0b6d6a64bcd9be4f9bbbc4b0824a3
Merge "Add Search and Category side panels"