fix(storages): the pool page measures its pool fresh, shares one clone dialog and says what it cannot show

- The page lists the volumes first: that refreshes the pool, and libvirt
  measures a pool's space only when it is refreshed, so the size and
  usage shown were as of the previous refresh.
- A space that cannot be read says so instead of 0 bytes, and the
  pool's status, read from the same pool info, no longer fails the
  page after it; a stopped pool says its space and volumes are
  unavailable until it is started, instead of 0 bytes and nothing.
- The API's pool is measured after the same refresh, and a stopped
  pool lists no volumes there instead of failing.
- A clone the job refuses (a name in use, a volume gone) is a message
  on the page, not a server error.
- An ISO image is recognised by its name (storages.jobs.is_iso):
  libvirt calls its format raw, so the template's "iso" check never
  disabled its Clone button. The clone job refuses one too; the upload
  uses the same rule.
- One clone dialog serves every volume, filled and reset by the button
  that opens it, instead of one dialog per volume in the page; its
  fields have labels and its title names the dialog.
- Volume rows are searched by name only (data-search), with a message
  when none matches, in a live region for screen readers; names show
  in full. The search script loads only
  with the volume table: on a stopped pool's page it failed for want
  of a search box. An empty pool says "This pool has no volumes".
- The unused wvmStorage.get_volumes_details goes: update_volumes is
  the same.

vrtManager/storage.py

@@ -281,21 +281,6 @@ class wvmStorage(wvmConnect):
     def refresh(self):
         return self.pool.refresh(0)
 
-    def get_volumes_details(self):
-        with contextlib.suppress(Exception):
-            self.refresh()
-
-        vols = self.get_volumes()
-        return [
-            {
-                "name": volname,
-                "size": self.get_volume_size(volname),
-                "allocation": self.get_volume_allocation(volname),
-                "type": self.get_volume_format_type(volname),
-            }
-            for volname in vols
-        ]
-
     def get_volume_details(self, volname):
         with contextlib.suppress(Exception):
             self.refresh()