Update get/delete_volume API to use versionedobjects

Update get/delete_volume API to use versionedobjects

The following patch updates get_volume and delete_volume
API to use volume versionedobjects.  Changes were made to
be backwards compatible with older RPC clients. It only
includes changes to the core cinder code.  Changes in the
drivers are left to each driver maintainer to update.

Note that this patch DOES NOT try to use
object dot notation everywhere, since it would
increase the size of the patch.  Instead, it
will be done in subsequent patches.

Co-Authored-By: Michal Dulko <michal.dulko@intel.com>
Co-Authored-By: Szymon Wroblewski <szymon.wroblewski@intel.com>
Change-Id: Ifb36726f8372e21d1d9825d6ab04a072e5db4a6a
Partial-Implements: blueprint cinder-objects