### 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.
register_extension_wrapper(memnew(OpenXRFBUpdateSwapchainExtension(p_rendering_driver)));
	register_extension_wrapper(memnew(OpenXRFBFoveationExtension(p_rendering_driver)));
	
	for (OpenXRExtensionWrapper *wrapper : registered_extension_wrappers) {
		wrapper->on_before_instance_created();
	}
	if (!load_layer_properties()) {
		destroy_instance();
		return false;
	}
	if (!load_supported_extensions()) {
		destroy_instance();
		return false;
	}
	if (!create_instance()) {
		destroy_instance();
		return false;
	}
	if (!resolve_instance_openxr_symbols()) {
		destroy_instance();
		return false;
	}
	if (!get_system_info()) {
		destroy_instance();
		return false;
	}
	if (!load_supported_view_configuration_types()) {
		destroy_instance();
		return false;
	}