### 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.
template = "#set ($bar = $input.path('$.foo')[1]) \n $bar"
        variables = {"input": {"body": {"foo": ["e1", "e2", "e3", "e4"]}}}
        result = ApiGatewayVtlTemplate().render_vtl(template, variables).strip()
        assert result == "e2"
        template = "#set ($bar = $input.path('$.foo')[1][1][1]) $bar"
        variables = {"input": {"body": {"foo": [["e1"], ["e2", ["e3", "e4"]]]}}}
        result = ApiGatewayVtlTemplate().render_vtl(template, variables).strip()
        assert result == "e4"
    def test_string_methods(self):
        context = {"foo": {"bar": "BAZ baz"}}
        variables = {"input": {"body": context}}
        template1 = "${foo.bar.strip().lower().replace(' ','-')}"
        template2 = "${foo.bar.trim().toLowerCase().replace(' ','-')}"
        for template in [template1, template2]:
            result = ApiGatewayVtlTemplate().render_vtl(template, variables=variables)
            assert result == "baz-baz"
    def test_render_urlencoded_string_data(self):
        template = "MessageBody=$util.base64Encode($input.json('$'))"
        variables = {"input": {"body": {"spam": "eggs"}}}
        result = ApiGatewayVtlTemplate().render_vtl(template, variables)
        assert result == "MessageBody=eyJzcGFtIjogImVnZ3MifQ=="
    def test_keyset_functions(self):
        template = "#set($list = $input.path('$..var1[1]').keySet()) #foreach($e in $list)$e#end"
        body = {"var1": [{"a": 1}, {"b": 2}]}
        variables = {"input": {"body": body}}
        result = ApiGatewayVtlTemplate().render_vtl(template, variables)
        assert result == " b"