Move Ui code model support into QtSupport

* Move basic ui code model support from CppTools into QtSupport
* Use Kit infrastructure to retrieve uicCommand and environment
* Remove specialization for cmake projects (no longer needed)
* Remove specialization for qmake based projects (no longer needed)

Change-Id: I8569cc01acb46a540883c2da235d169bebf7db39
Reviewed-by: Daniel Teske <daniel.teske@digia.com>