Concept of integration of QDS into QtC

Currently we use the info bar to notify users that .qmlprojects and ui.qml files should be opned in QDS instead of QtC.

This requires UX polish.

Suggestions:

"A design mode" that instead of the current design mode contains a info page about QDS and QDS specific options like "open .ui.qml files always in QDS".

The goal is to create visiblity for QDS and inegrate QDS into the QtC workflow.