Add values for empty sahara dropdown boxes

Currently if no templates or images are available then the drop down
boxes simply appear empty, this patch adds "No Images Available" and
"No Templates Available" as the first item in each list if they are
empty.

Change-Id: I4bfed9b53f5ac9f031c23a15270b996f7d153be5
Closes-Bug: 1391343
Imported Translations from Transifex

For more information about this automatic import see:
https://wiki.openstack.org/wiki/Translations/Infrastructure

Change-Id: Ia5990fa4587bb1ab1eab715764d33a1c9cd7108e
Merge "Add values for empty sahara dropdown boxes"