fix #934 Missing and duplicate tests in the suite

1) `test.aria.utils.dragdrop.DragDropBean` is included later via `test.aria.utils.dragdrop.DragTestSuite`
2) Seems that `FocusHandlingTestCase` was a duplicate for 6 months while `FocusCheckTestCase` was missing (probably a copy-paste error) and no one noticed. Time to work on #924 finally?