### 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.
ADD_SIGNAL(MethodInfo("session_begun"));
	ADD_SIGNAL(MethodInfo("session_stopping"));
	ADD_SIGNAL(MethodInfo("session_focussed"));
	ADD_SIGNAL(MethodInfo("session_visible"));
	ADD_SIGNAL(MethodInfo("pose_recentered"));
	
	ClassDB::bind_method(D_METHOD("get_display_refresh_rate"), &OpenXRInterface::get_display_refresh_rate);
	ClassDB::bind_method(D_METHOD("set_display_refresh_rate", "refresh_rate"), &OpenXRInterface::set_display_refresh_rate);
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "display_refresh_rate"), "set_display_refresh_rate", "get_display_refresh_rate");
	
	ClassDB::bind_method(D_METHOD("get_render_target_size_multiplier"), &OpenXRInterface::get_render_target_size_multiplier);
	ClassDB::bind_method(D_METHOD("set_render_target_size_multiplier", "multiplier"), &OpenXRInterface::set_render_target_size_multiplier);
	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "render_target_size_multiplier"), "set_render_target_size_multiplier", "get_render_target_size_multiplier");
	
	ClassDB::bind_method(D_METHOD("is_foveation_supported"), &OpenXRInterface::is_foveation_supported);
	ClassDB::bind_method(D_METHOD("get_foveation_level"), &OpenXRInterface::get_foveation_level);
	ClassDB::bind_method(D_METHOD("set_foveation_level", "foveation_level"), &OpenXRInterface::set_foveation_level);
	ADD_PROPERTY(PropertyInfo(Variant::INT, "foveation_level"), "set_foveation_level", "get_foveation_level");
	ClassDB::bind_method(D_METHOD("get_foveation_dynamic"), &OpenXRInterface::get_foveation_dynamic);
	ClassDB::bind_method(D_METHOD("set_foveation_dynamic", "foveation_dynamic"), &OpenXRInterface::set_foveation_dynamic);
	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "foveation_dynamic"), "set_foveation_dynamic", "get_foveation_dynamic");
	
	ClassDB::bind_method(D_METHOD("is_action_set_active", "name"), &OpenXRInterface::is_action_set_active);