Widget tree is displayed and basic role mapping is available.
Still needs quite some work (positions, actions, texts, etc.)

Change-Id: I9d26a762f1d9684f33bbb80a384cf2a0b8a905c0
Reviewed-on: https://gerrit.libreoffice.org/60853
Tested-by: Jenkins
Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>