Test latest released Pyside release with preview version of Creator

Create test suite for preview Creator testing set to cover Pyside testing. Use stable version of Pyside, which would be the latest released. Include also latest released LTS version.

If possible, create test suite so that it could be run also in Pyside project (with released Creator and preview Pyside version).

Test should include at least following test:

• verify Pyside is registered to Creator and no errors in UI
• new pyside projects can be created with the new project wizard and executed
• existing pyside projects can be opened in Creator and executed (to be defined, what is 'existing pyside project', maybe pyside examples?)