### 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

‮
if (parameter->initializer != nullptr) {
				default_used = true;
			} else {
				if (default_used) {
					push_error("Cannot have a mandatory parameters after optional parameters.");
					continue;
				}
			}
			if (p_function->parameters_indices.has(parameter->identifier->name)) {
				push_error(vformat(R"(Parameter with name "%s" was already declared for this %s.)", parameter->identifier->name, p_type));
			} else {
				p_function->parameters_indices[parameter->identifier->name] = p_function->parameters.size();
				p_function->parameters.push_back(parameter);
				p_body->add_local(parameter, current_function);
			}
		} while (match(GDScriptTokenizer::Token::COMMA));
	}
	pop_multiline();
	consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, vformat(R"*(Expected closing ")" after %s parameters.)*", p_type));
	if (match(GDScriptTokenizer::Token::FORWARD_ARROW)) {
		make_completion_context(COMPLETION_TYPE_NAME_OR_VOID, p_function);
		p_function->return_type = parse_type(true);
		if (p_function->return_type == nullptr) {
			push_error(R"(Expected return type or "void" after "->".)");
		}
	}
	
	consume(GDScriptTokenizer::Token::COLON, vformat(R"(Expected ":" after %s declaration.)", p_type));
}
GDScriptParser::FunctionNode *GDScriptParser::parse_function() {