### 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.
XrSpaceLocation location = {
		XR_TYPE_SPACE_LOCATION, 
		&velocity, 
		0, 
		{
				{ 0.0, 0.0, 0.0, 0.0 }, 
				{ 0.0, 0.0, 0.0 } 
		} 
	};
	result = xrLocateSpace(view_space, play_space, display_time, &location);
	if (XR_FAILED(result)) {
		print_line("OpenXR: Failed to locate view space in play space [", get_error_string(result), "]");
		return XRPose::XR_TRACKING_CONFIDENCE_NONE;
	}
	XRPose::TrackingConfidence confidence = transform_from_location(location, r_transform);
	parse_velocities(velocity, r_linear_velocity, r_angular_velocity);
	if (head_pose_confidence != confidence) {
		
		head_pose_confidence = confidence;
		if (head_pose_confidence == XRPose::XR_TRACKING_CONFIDENCE_NONE) {
			print_line("OpenXR head space location not valid (check tracking?)");
		} else if (head_pose_confidence == XRPose::XR_TRACKING_CONFIDENCE_LOW) {
			print_verbose("OpenVR Head pose now tracking with low confidence");
		} else {
			print_verbose("OpenVR Head pose now tracking with high confidence");
		}
	}
	return confidence;
}
bool OpenXRAPI::get_view_transform(uint32_t p_view, Transform3D &r_transform) {