Starting in volume API microversion 3.52, it is possible to filter
volume types by extra specs (a.k.a. properties). Even non-admins can do
this for so-called "user visible" extra specs. Make it possible to do
this.
While we're here, the test file is renamed to match the name of the
module under test.
Change-Id: Ia9acc06c0c615bf24e12b63146ea97ac2505f596
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>