### 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.
context_var = variables.get("context") or {}
        stage_var = variables.get("stage_variables") or {}
        namespace = {
            "context": context_var,
            "stageVariables": stage_var,
        }
        return namespace
def render_velocity_template(template, context, variables=None, as_json=False):
    context = context or {}
    context.update(variables or {})
    return VtlTemplate().render_vtl(template, context, as_json=as_json)
airspeed.MacroDefinition.RESERVED_NAMES = airspeed.MacroDefinition.RESERVED_NAMES + ("return",)
@patch(airspeed.VariableExpression.calculate)
def calculate(fn, self, *args, **kwarg):
    result = fn(self, *args, **kwarg)
    result = "" if result is None else result
    return result
class ReturnDirective(airspeed.EvaluateDirective):