Support other input methods on Popup/Dialogs' _input_from_window

[rsubtil]

The Popup/Dialog's _input_from_window callback was only listening for keyboard events. Therefore, other input methods (like game controllers) couldn't be used, notably for closing windows.

Fixes #80425

[Sauermann]

If there isn't any conceptual reason for requiring a keyboard for the "ui_cancel"-action, then I find this implementation fitting.

[rsubtil]

If there isn't any conceptual reason for requiring a keyboard for the "ui_cancel"-action, then I find this implementation fitting.

This looks like a remnant of old code, ever since the Window refactoring:

godot/scene/gui/popup.cpp

Lines 37 to 42 in 441f1a5

	void Popup::_input_from_window(const Ref<InputEvent> &p_event) {
	Ref<InputEventKey> key = p_event;
	if (key.is_valid() && key->is_pressed() && key->get_keycode() == KEY_ESCAPE) {
	_close_pressed();
	}
	}

This used to be hardcoded to the Escape key, and then recently changed to use the ui_cancel with #77297

[akien-mga]

Thanks!