### 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.
String runtime_name;
	String runtime_version;
	
	XrFormFactor form_factor = XR_FORM_FACTOR_HEAD_MOUNTED_DISPLAY;
	XrViewConfigurationType view_configuration = XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO;
	XrReferenceSpaceType reference_space = XR_REFERENCE_SPACE_TYPE_STAGE;
	bool submit_depth_buffer = false; 
	
	XrEnvironmentBlendMode environment_blend_mode = XR_ENVIRONMENT_BLEND_MODE_OPAQUE;
	uint32_t num_supported_environment_blend_modes = 0;
	XrEnvironmentBlendMode *supported_environment_blend_modes = nullptr;
	
	XrInstance instance = XR_NULL_HANDLE;
	XrSystemId system_id = 0;
	String system_name;
	uint32_t vendor_id = 0;
	XrSystemTrackingProperties tracking_properties;
	XrSession session = XR_NULL_HANDLE;
	XrSessionState session_state = XR_SESSION_STATE_UNKNOWN;
	bool running = false;
	XrFrameState frame_state = { XR_TYPE_FRAME_STATE, NULL, 0, 0, false };
	double render_target_size_multiplier = 1.0;
	OpenXRGraphicsExtensionWrapper *graphics_extension = nullptr;
	XrSystemGraphicsProperties graphics_properties;
	uint32_t view_count = 0;
	XrViewConfigurationView *view_configuration_views = nullptr;
	XrView *views = nullptr;
	XrCompositionLayerProjectionView *projection_views = nullptr;
	XrCompositionLayerDepthInfoKHR *depth_views = nullptr; 
	enum OpenXRSwapChainTypes {