enh(test): add qtContainer support tu ut
Description
The present unit test handling does not support tContainer creation.
This blocks the unit testing of all widget services, which strongly rely qtcontainers.
Proposal
Add a tuQtContainer which is empty, to the unit test framework to make it possible to start services with qtcontainres in ut.
Functional specifications
Workflow, UX/UI design, screenshots, etc...
Technical specifications
Details of the implementation
Test plan
Describe how you will verify that the implementation fulfils the specifications