DataFormWidget: Fix some UI issues

- Textview: Wrap text, set padding
- ListMultiTreeView: Align checkboxes to the right
- Add a adjustment element that sets default sizes on the columns
- Allow two new options 'form-width' and 'left-width' to customize sizes
3 jobs from master in 4 minutes and 2 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #9187
run-appdata

00:00:09

passed #9186
run-tests

00:03:43

 
  Build
passed #9188
run-build

00:00:10