Support potentially polymorphic calls

[mabar]

Is your feature request related to a problem? Please describe.

In PHP I can click through from method definition to its usage and from usage to definition even if the method does not exist on the current class but only on a child class. Technically wrong but useful when dealing with legacy code or generics.

class Form {}

interface Control {}

abstract class BaseControl implements Control {
    public const Form = 'form';
    public Form $form;
    public function getForm(): Form
    {
        return new Form();
    }
}

class AnotherControl implements Control {}

function smth(Control $control) {
    echo $control::Form;
    echo $control->form;
    echo $control->getForm();
}

This also applies to constants and properties

Describe the solution you'd like

Same as in PHP:

• make click-through from definition to usage work (and vice versa)
• add notice about potencially polymorphic call (for PHP IDE adds it only when two or more class childs exist, but it would make sense to report polymorphic call even if just one possible choice exists because it is still wrong code)
• don't hint the method when writing code (already behaves that way and should stay that way)