ui_test_core: address pylint warnings and enable coding style test

See merge request !1589
10 jobs for feat/Formulator-validate-TALES
Status Job ID Name Coverage
  External
failed ERP5.UnitTest-Master

01:20:03

passed SlapOS.Eggs.UnitTest-Master.Python2

00:25:59

passed SlapOS.Eggs.UnitTest-Master.Python3

00:14:06

failed ERP5.UnitTest-Master

failed ERP5.UnitTest-Master

02:22:11

passed SlapOS.Eggs.UnitTest-Master.Python2

00:25:46

passed SlapOS.Eggs.UnitTest-Master.Python2

00:27:14

passed SlapOS.Eggs.UnitTest-Master.Python3

00:25:47

passed SlapOS.Eggs.UnitTest-Master.Python3

passed SlapOS.Eggs.UnitTest-Master.Python3

00:24:28