### Godot version

3b086aa06

### System information

ArchLinux x11

### Issue description

```gdscript
extends Node

@export_group("My Properties")
@export var number = 3
@export var string = ""

@export_group("Prefixed Properties", "prefix_")
@export var prefix_number = 3
@export var prefix_string = ""

@export_group("", "")
@export var ungrouped_number = 3
```

![image](https://user-images.githubusercontent.com/70787919/214983963-528c415b-745b-47fc-9777-36ebe31a3060.png)


### Steps to reproduce

- create script
- @export_group
- go inspector

### Minimal reproduction project

‮
register_annotation(MethodInfo("@export_category", PropertyInfo(Variant::STRING, "name")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_CATEGORY>);
	register_annotation(MethodInfo("@export_group", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::STRING, "prefix")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_GROUP>, varray(""));
	register_annotation(MethodInfo("@export_subgroup", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::STRING, "prefix")), AnnotationInfo::STANDALONE, &GDScriptParser::export_group_annotations<PROPERTY_USAGE_SUBGROUP>, varray(""));
	
	register_annotation(MethodInfo("@warning_ignore", PropertyInfo(Variant::STRING, "warning")), AnnotationInfo::CLASS | AnnotationInfo::VARIABLE | AnnotationInfo::SIGNAL | AnnotationInfo::CONSTANT | AnnotationInfo::FUNCTION | AnnotationInfo::STATEMENT, &GDScriptParser::warning_annotations, varray(), true);
	
	register_annotation(MethodInfo("@rpc", PropertyInfo(Variant::STRING, "mode"), PropertyInfo(Variant::STRING, "sync"), PropertyInfo(Variant::STRING, "transfer_mode"), PropertyInfo(Variant::INT, "transfer_channel")), AnnotationInfo::FUNCTION, &GDScriptParser::rpc_annotation, varray("", "", "", 0), true);
#ifdef DEBUG_ENABLED
	is_ignoring_warnings = !(bool)GLOBAL_GET("debug/gdscript/warnings/enable");
#endif
}
GDScriptParser::~GDScriptParser() {
	clear();
}
void GDScriptParser::clear() {
	while (list != nullptr) {
		Node *element = list;
		list = list->next;
		memdelete(element);
	}
	head = nullptr;
	list = nullptr;
	_is_tool = false;
	for_completion = false;
	errors.clear();
	multiline_stack.clear();
	nodes_in_progress.clear();
}
void GDScriptParser::push_error(const String &p_message, const Node *p_origin) {