### 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.
XrResult try_get_instance_proc_addr(const char *p_name, PFN_xrVoidFunction *p_addr);
	XrResult get_instance_proc_addr(const char *p_name, PFN_xrVoidFunction *p_addr);
	String get_error_string(XrResult result);
	String get_swapchain_format_name(int64_t p_swapchain_format) const;
	void set_xr_interface(OpenXRInterface *p_xr_interface);
	static void register_extension_wrapper(OpenXRExtensionWrapper *p_extension_wrapper);
	static void unregister_extension_wrapper(OpenXRExtensionWrapper *p_extension_wrapper);
	static void register_extension_metadata();
	static void cleanup_extension_wrappers();
	void set_form_factor(XrFormFactor p_form_factor);
	XrFormFactor get_form_factor() const { return form_factor; }
	void set_view_configuration(XrViewConfigurationType p_view_configuration);
	XrViewConfigurationType get_view_configuration() const { return view_configuration; }
	void set_reference_space(XrReferenceSpaceType p_reference_space);
	XrReferenceSpaceType get_reference_space() const { return reference_space; }
	void set_submit_depth_buffer(bool p_submit_depth_buffer);
	bool get_submit_depth_buffer() const { return submit_depth_buffer; }
	bool is_initialized();
	bool is_running();
	bool initialize(const String &p_rendering_driver);
	bool initialize_session();
	void finish();
	XrSpace get_play_space() const { return play_space; }