neutron 'quota_details' extension was added in Pike to provide
a convenient way to retrieve resource usage in neutron without listing
individual resources. It was added in Pike release and we will have
six releases since then once Ussuri release is shipped. Enough time has
passed to migrate it to the new mechanism, so it is time to deprecate
the legacy way for future cleanup.
Change-Id: Ie0b4613bf9fdcd96481b3bb1139b4fb153bfef83