[Form] Add TypeProvider for Form::get

[King2500]

It would be cool, if you could implement a TypeProvider for Form::get('child') method result.

PhpStorm can't understand the correct result, because of the generic FormInterface:

You already "detect" the Form types when autocompleting: (though FormInterface and FormTypes are not the same here)

In this case its return type is Symfony\Component\Form\SubmitButton.

Known types from Form component (implementing FormInterface):

• Symfony\Component\Form\Button
• Symfony\Component\Form\SubmitButton

All other form fields are of type:

• Symfony\Component\Form\Form

I think this could work similar to your get('service') TypeProvider?

[Haehnchen]

get was blocked by service container type provider. this api limit was hopefully fixed in phpstorm8. we will see :)