### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

`#return` macro for AppSync is not supported

```
- ["Error in template '<string>' at position 48-60 in expression: #return($v1)\nException: no such macro: return\n\nGraphQL request:3:11\n2 |         {\n3 |           hi2 {\n  |           ^\n4 |             value"] None
```

### Expected Behavior

`#return` is a valid command in AppSync Resolver Velocity request and response templates.

https://docs.aws.amazon.com/appsync/latest/devguide/aws-appsync-directives.html 

### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    localstack start

#### Client commands (e.g., AWS SDK code snippet, or sequence of "awslocal" commands)

1. `CDKDeployment`
2. GraphQL Rest API to `localstack`

3. AppSync resolver with response template:

```vtl
#set($v1 = {})
$util.qr($v1.put('value', 'hi'))
#return($v1)"
```

```sdl
schema {
  query: Query
}
type valueObj {
  value: String
}
type Query {
  hi2: valueObj
}
```

4. Query AppSync

```sdl
Query {
   hi2
}
```



### Environment

```markdown
- OS: Ubuntu/WSL2
- LocalStack: 0.14.2.1
```


### Anything else?

The same code runs fine on AWS/AppSync.
return ExtendedString(self.lower())
            def toUpperCase(self, *_, **__):
                return ExtendedString(self.upper())
        def apply(obj, **_):
            if isinstance(obj, dict):
                for k, v in obj.items():
                    if isinstance(v, str):
                        obj[k] = ExtendedString(v)
            return obj
        
        
        variables = copy.deepcopy(variables or {})
        recurse_object(variables, apply)
        
        t = airspeed.Template(template)
        namespace = self.prepare_namespace(variables)
        
        
        input_var = variables.get("input") or {}
        dict_pack = input_var.get("body")
        if isinstance(dict_pack, dict):
            for k, v in dict_pack.items():
                namespace.update({k: v})
        rendered_template = t.merge(namespace)
        
        rendered_template = rendered_template.replace(empty_placeholder, "")
        if as_json:
            rendered_template = json.loads(rendered_template)
        return rendered_template
    def prepare_namespace(self, variables) -> Dict: