[FEATURE] Make it possible to assign variables to the view

[georgringer]

Using a slot is nice but currently there is no way to assign items to the view besides using xclass. E.g. https://github.com/thomasrawiel/powermailcaptcha/blob/develop/Classes/Controller/FormController.php as example

• setSettings can't be used because the settings are assigned to the view way earlier
• changing the slot is not an option because breaking