Cyborg evacuate support

This change extends the conductor manager
to append the cyborg resource request to the
request spec when performing an evacuate.

This change passes the ARQs to spawn during rebuild
and evacuate. On evacuate the existing ARQs will be deleted
and new ARQs will be created and bound, during rebuild the
existing ARQs are reused.

This change extends the rebuild_instance compute rpcapi
function to carry the arq_uuids. This eliminates the
need to lookup the uuids associated with the arqs assinged
to the instance by quering cyborg.

Co-Authored-By: Wenping Song <songwenping@inspur.com>
Co-Authored-By: Brin Zhang <zhangbailin@inspur.com>

Implements: blueprint cyborg-rebuild-and-evacuate
Change-Id: I147bf4d95e6d86ff1f967a8ce37260730f21d236

api-guide/source/accelerator-support.rst

@@ -29,9 +29,8 @@ appropriate privileges) must do the following:
 
     openstack server create --flavor $myflavor --image $myimage $servername
 
-As of 21.0.0 (Ussuri), nova supports only specific operations for instances
-with accelerators. The lists of supported and unsupported operations are as
-below:
+Nova supports only specific operations for instances with accelerators.
+The lists of supported and unsupported operations are as below:
 
 * Supported operations.
 
@@ -42,17 +41,21 @@ below:
   * Take a snapshot.
   * Backup.
   * Rescue and unrescue.
+  * Rebuild.
+  * Evacuate.
 
 * Unsupported operations
 
-  * Rebuild.
   * Resize.
-  * Evacuate.
   * Suspend and resume.
   * Shelve and unshelve.
   * Cold migration.
   * Live migration.
 
+.. versionchanged:: 22.0.0(Victoria)
+
+   Added support for rebuild and evacuate operations.
+
 Some operations, such as lock and unlock, work as they are effectively
 no-ops for accelerators.