### 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 {
            "context": api_context.context or {},
            "stage_variables": api_context.stage_variables or {},
            "input": {
                "body": api_context.data_as_string(),
                "params": {
                    "path": api_context.path_params,
                    "querystring": api_context.query_params(),
                    "header": api_context.headers,
                },
            },
        }
class RequestTemplates(Templates):
    """
    Handles request template rendering
    """
    def render(self, api_context: ApiInvocationContext):
        LOG.info(
            "Method request body before transformations: %s", to_str(api_context.data_as_string())
        )
        request_templates = api_context.integration.get("requestTemplates", {})
        template = request_templates.get(APPLICATION_JSON, {})
        if not template:
            return api_context.data_as_string()
        variables = self.build_variables_mapping(api_context)
        result = self.render_vtl(template, variables=variables)
        LOG.info(f"Endpoint request body after transformations:\n{result}")
        return result
class ResponseTemplates(Templates):