Resource retrieving: add changes-before filter

This adds the changes-before filter to the servers,
os-instance-actions and os-migrations APIs for
filtering resources which were last updated before
or equal to the given time. The changes-before filter,
like the changes-since filter, will return deleted
server resources.

Part of bp support-to-query-nova-resources-filter-by-changes-before
Change-Id: If91c179e3823c8b0da744a9363906b0f7b05c326

nova/api/openstack/api_version_request.py

@@ -158,6 +158,10 @@ REST_API_VERSION_HISTORY = """REST API Version History:
              /os-server-groups/{group_id} API.
     * 2.65 - Add support for abort live migrations in ``queued`` and
              ``preparing`` status.
+    * 2.66 - Add ``changes-before`` to support users to specify the
+             ``updated_at`` time to filter nova resources, the resources
+             include the servers API, os-instance-action API and
+             os-migrations API.
 """
 
 # The minimum and maximum versions of the API supported
@@ -166,7 +170,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
 # Note(cyeoh): This only applies for the v2.1 API once microversions
 # support is fully merged. It does not affect the V2 API.
 _MIN_API_VERSION = "2.1"
-_MAX_API_VERSION = "2.65"
+_MAX_API_VERSION = "2.66"
 DEFAULT_API_VERSION = _MIN_API_VERSION
 
 # Almost all proxy APIs which are related to network, images and baremetal