### 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.
virtual bool initialize() override;
	virtual void uninitialize() override;
	virtual Dictionary get_system_info() override;
	virtual void trigger_haptic_pulse(const String &p_action_name, const StringName &p_tracker_name, double p_frequency, double p_amplitude, double p_duration_sec, double p_delay_sec = 0) override;
	virtual bool supports_play_area_mode(XRInterface::PlayAreaMode p_mode) override;
	virtual XRInterface::PlayAreaMode get_play_area_mode() const override;
	virtual bool set_play_area_mode(XRInterface::PlayAreaMode p_mode) override;
	float get_display_refresh_rate() const;
	void set_display_refresh_rate(float p_refresh_rate);
	Array get_available_display_refresh_rates() const;
	bool is_action_set_active(const String &p_action_set) const;
	void set_action_set_active(const String &p_action_set, bool p_active);
	Array get_action_sets() const;
	double get_render_target_size_multiplier() const;
	void set_render_target_size_multiplier(double multiplier);
	bool is_foveation_supported() const;
	int get_foveation_level() const;
	void set_foveation_level(int p_foveation_level);
	bool get_foveation_dynamic() const;
	void set_foveation_dynamic(bool p_foveation_dynamic);
	virtual Size2 get_render_target_size() override;
	virtual uint32_t get_view_count() override;
	virtual Transform3D get_camera_transform() override;
	virtual Transform3D get_transform_for_view(uint32_t p_view, const Transform3D &p_cam_transform) override;
	virtual Projection get_projection_for_view(uint32_t p_view, double p_aspect, double p_z_near, double p_z_far) override;
	virtual RID get_color_texture() override;
	virtual RID get_depth_texture() override;
	virtual void process() override;
	virtual void pre_render() override;
	bool pre_draw_viewport(RID p_render_target) override;