Small performance improvement

We can use search_opts for volume_list and volume_snapshot_list
instead of filtering the results after we get the whole list to
improve the performance.

Change-Id: Ieb7833038228c97f7415bd57ecd353e218f00cdd
Closes-bug: #1401013
Make admin_state translatable

In several panels the network admin state is hardcoded to UP/DOWN,
this patch aims to make the admin_state translatable.

Change-Id: Ia0e5ba02a4980c1db0d914e2689956feee5fb718
Closes-bug: #1390207
Merge "Make admin_state translatable"
Merge "Small performance improvement"