test: use SavedTestSuite

Reduce the test installation time.

It would be nice to include the configurator too.

test/__init__.py

 # test_suite is provided by 'run_test_suite'
 from glob import glob
-from test_suite import ERP5TypeTestSuite
+from test_suite import SavedTestSuite
 import os, subprocess, re
 import sys
 
 
-class OfficeJS(ERP5TypeTestSuite):
+class OfficeJS(SavedTestSuite):
     """
     """
+    _saved_test_id = "officejs_test:testOfficeJSAppstoreMixin"
     def getTestList(self):
       test_list = []
       path = sys.path[0]