python 3 updates

- Fix super() calls for python 3
- No need to inherit objects.
- No need for u at the start of strings
- Tidied up some brackets and f-strings too

web/pgadmin/tools/backup/__init__.py

@@ -34,7 +34,7 @@ server_info = {}
 
 class BackupModule(PgAdminModule):
     """
-    class BackupModule(Object):
+    class BackupModule():
 
         It is a utility which inherits PgAdminModule
         class and define methods to load its own
@@ -64,7 +64,7 @@ blueprint = BackupModule(
 )
 
 
-class BACKUP(object):
+class BACKUP():
     """
     Constants defined for Backup utilities
     """

web/pgadmin/tools/backup/tests/test_backup_create_job_unit_test.py

@@ -12,7 +12,7 @@ import os
 
 from pgadmin.utils.route import BaseTestGenerator
 from regression import parent_node_dict
-from pgadmin.utils import server_utils as server_utils, does_utility_exist
+from pgadmin.utils import server_utils, does_utility_exist
 from pgadmin.browser.server_groups.servers.databases.tests import utils as \
     database_utils
 from unittest.mock import patch, MagicMock