Filter volumes and snapshots by query string

Filter volumes and snapshots by query string

Fix query string search_opts filters in api.openstack.volume.volumes and
snapshots.  Fix get_all methods in volumes.api to adequately handle
parameter matching.

The current api does not properly apply query string filters by
display_name, status, or (in the case of snapshots) volume_id.  These
filters are needed both for the end user and operator to display logical
grouping of these resources.

Fixes: bug #1046353
Change-Id: Ia12ffe1bf8a27c8a78daa24c4b728b394932a2b0