### 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.
Vector<const char *> extension_ptrs;
	for (int i = 0; i < enabled_extensions.size(); i++) {
		print_verbose(String("OpenXR: Enabling extension ") + String(enabled_extensions[i]));
		extension_ptrs.push_back(enabled_extensions[i].get_data());
	}
	
	String project_name = GLOBAL_GET("application/config/name");
	
	XrApplicationInfo application_info{
		"", 
		1, 
		"Godot Game Engine", 
		VERSION_MAJOR * 10000 + VERSION_MINOR * 100 + VERSION_PATCH, 
		XR_CURRENT_API_VERSION 
	};
	void *next_pointer = nullptr;
	for (OpenXRExtensionWrapper *wrapper : registered_extension_wrappers) {
		void *np = wrapper->set_instance_create_info_and_get_next_pointer(next_pointer);
		if (np != nullptr) {
			next_pointer = np;
		}
	}
	XrInstanceCreateInfo instance_create_info = {
		XR_TYPE_INSTANCE_CREATE_INFO, 
		next_pointer, 
		0, 
		application_info, 
		0, 
		nullptr, 
		uint32_t(extension_ptrs.size()),