### 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.
if (!create_swapchains()) {
		return false;
	}
	
	running = true;
	for (OpenXRExtensionWrapper *wrapper : registered_extension_wrappers) {
		wrapper->on_state_ready();
	}
	if (xr_interface) {
		xr_interface->on_state_ready();
	}
	
	return true;
}
bool OpenXRAPI::on_state_synchronized() {
	print_verbose("On state synchronized");
	
	List<RID> trackers;
	tracker_owner.get_owned_list(&trackers);
	for (int i = 0; i < trackers.size(); i++) {
		tracker_check_profile(trackers[i]);
	}
	for (OpenXRExtensionWrapper *wrapper : registered_extension_wrappers) {
		wrapper->on_state_synchronized();
	}
	return true;
}
bool OpenXRAPI::on_state_visible() {