### Godot version

4.2.dev 80de898d721f952dac0b102d48bb73d6b02ee1e8

### System information

OpenXR

### Issue description

The Godot 3 OpenXR plugin supported obtaining boundary/guardian information in order to obtain play space logic. While we do have a function in the `XRInterface` in Godot 4 that is supposed to retrieve this information (`get_play_area`) it is not implemented on the Godot 4 `OpenXRInterface`.

This logic needs to be ported.

### Steps to reproduce

Call `get_play_area`, be amazed by it not returning data :P

### Minimal reproduction project

Any XR project.
Ref<XRPositionalTracker> positional_tracker;
	positional_tracker.instantiate();
	
	if (p_tracker_name == "/user/hand/left") {
		positional_tracker->set_tracker_type(XRServer::TRACKER_CONTROLLER);
		positional_tracker->set_tracker_name("left_hand");
		positional_tracker->set_tracker_desc("Left hand controller");
		positional_tracker->set_tracker_hand(XRPositionalTracker::TRACKER_HAND_LEFT);
	} else if (p_tracker_name == "/user/hand/right") {
		positional_tracker->set_tracker_type(XRServer::TRACKER_CONTROLLER);
		positional_tracker->set_tracker_name("right_hand");
		positional_tracker->set_tracker_desc("Right hand controller");
		positional_tracker->set_tracker_hand(XRPositionalTracker::TRACKER_HAND_RIGHT);
	} else {
		positional_tracker->set_tracker_type(XRServer::TRACKER_CONTROLLER);
		positional_tracker->set_tracker_name(p_tracker_name);
		positional_tracker->set_tracker_desc(p_tracker_name);
	}
	positional_tracker->set_tracker_profile(INTERACTION_PROFILE_NONE);
	xr_server->add_tracker(positional_tracker);
	
	tracker = memnew(Tracker);
	tracker->tracker_name = p_tracker_name;
	tracker->tracker_rid = tracker_rid;
	tracker->positional_tracker = positional_tracker;
	tracker->interaction_profile = RID();
	trackers.push_back(tracker);
	return tracker;
}
void OpenXRInterface::tracker_profile_changed(RID p_tracker, RID p_interaction_profile) {