### 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.
ERR_FAIL_COND_V(instance == XR_NULL_HANDLE, false);
	XrEventDataBuffer runtimeEvent;
	runtimeEvent.type = XR_TYPE_EVENT_DATA_BUFFER;
	runtimeEvent.next = nullptr;
	
	XrResult pollResult = xrPollEvent(instance, &runtimeEvent);
	while (pollResult == XR_SUCCESS) {
		bool handled = false;
		for (OpenXRExtensionWrapper *wrapper : registered_extension_wrappers) {
			handled |= wrapper->on_event_polled(runtimeEvent);
		}
		switch (runtimeEvent.type) {
			case XR_TYPE_EVENT_DATA_EVENTS_LOST: {
				XrEventDataEventsLost *event = (XrEventDataEventsLost *)&runtimeEvent;
				
				WARN_PRINT("OpenXR EVENT: " + itos(event->lostEventCount) + " event data lost!");
			} break;
			case XR_TYPE_EVENT_DATA_VISIBILITY_MASK_CHANGED_KHR: {
				
				
				
				
				print_verbose("OpenXR EVENT: STUB: visibility mask changed");
			} break;