Add option to the wizard to create or select a virtual environment

Motivation

Other IDEs like PyCharm offer the option to create or use an existing virtual environment when starting a project, we could add a new page or modify one of the current ones to include this functionality (attached image).

Implications

This might modify a bit the logic on the next steps, because we do ask if PySide 2 or PySide 6 will be used, meaning that we could check if 'an existent virtual environment' is selected, to check if a PySide was installed.