### 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(instance == XR_NULL_HANDLE);
	if (!running) {
		return;
	}
	
	
	
	
	XrFrameWaitInfo frame_wait_info = { XR_TYPE_FRAME_WAIT_INFO, nullptr };
	frame_state.predictedDisplayTime = 0;
	frame_state.predictedDisplayPeriod = 0;
	frame_state.shouldRender = false;
	XrResult result = xrWaitFrame(session, &frame_wait_info, &frame_state);
	if (XR_FAILED(result)) {
		print_line("OpenXR: xrWaitFrame() was not successful [", get_error_string(result), "]");
		
		frame_state.predictedDisplayTime = 0;
		frame_state.predictedDisplayPeriod = 0;
		frame_state.shouldRender = false;
		return;
	}
	if (frame_state.predictedDisplayPeriod > 500000000) {