(core) update tests after jenkins engine freshening

Summary:
After updating the jenkins test workers, chrome and python changes resulting in a scattering of test failures.

 * Clicking on an icon that has been transformed to mirror around the y axis fails via selenium. Not sure why. "Fixed" by asking the browser to do the click.
 * There was a small change from python 3.9.6 to python 3.9.7 that affected completion of property attributes.

Worker updates here: https://phab.getgrist.com/D3029

Test Plan: these tests

Reviewers: alexmojaki

Reviewed By: alexmojaki

Differential Revision: https://phab.getgrist.com/D3031

sandbox/grist/test_completion.py

@@ -212,9 +212,14 @@ class TestCompletion(test_engine.EngineTestCase):
 
   def test_suggest_lookup_methods(self):
     # Should suggest lookup formulas for tables.
-    self.assertEqual(self.engine.autocomplete("Address.", "Students", "firstName", self.user), [
-      ('Address.Record', '', True),
-      ('Address.RecordSet', '', True),
+    address_dot_completion = self.engine.autocomplete("Address.", "Students", "firstName", self.user)
+    # In python 3.9.7, rlcompleter stops adding parens for property attributes,
+    # see https://bugs.python.org/issue44752 - seems like a minor issue, so leave test
+    # tolerant.
+    property_aware_completer = address_dot_completion[0] == 'Address.Record'
+    self.assertEqual(address_dot_completion, [
+      'Address.Record' if property_aware_completer else ('Address.Record', '', True),
+      'Address.RecordSet' if property_aware_completer else ('Address.RecordSet', '', True),
       'Address.all',
       ('Address.lookupOne', '(colName=<value>, ...)', True),
       ('Address.lookupRecords', '(colName=<value>, ...)', True),