D29210: [NestedListHelper] Fix indentation of selection, add tests

[David Faure]

dfaure accepted this revision.
This revision is now accepted and ready to land.

BRANCH
  change-indent (branched from master)

REVISION DETAIL
  https://phabricator.kde.org/D29210

To: poboiko, #frameworks, dfaure, mlaurent
Cc: kde-frameworks-devel