### 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 (!running) {
		return false;
	}
	
	if (frame_state.predictedDisplayTime == 0) {
		return false;
	}
	
	if (views == nullptr || !view_pose_valid) {
		return false;
	}
	
	r_transform = transform_from_pose(views[p_view].pose);
	return true;
}
bool OpenXRAPI::get_view_projection(uint32_t p_view, double p_z_near, double p_z_far, Projection &p_camera_matrix) {