### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

Currently the VTL template for `request_templates` is not processed properly:

```
#set( $body = $input.json("$") )

#macro( loop $map )
{
    #foreach($key in $map.keySet())
        #set( $k = $util.escapeJavaScript($key) )
        #set( $v = $util.escapeJavaScript($map.get($key)).replaceAll("\\'", "'") )
        "$k": "$v"
        #if( $foreach.hasNext ) , #end
    #end
}
#end

{
    "enhancedAuthContext": #loop($context.authorizer),

    "headers": #loop($input.params().header),

    "query": #loop($input.params().querystring),

    "path": #loop($input.params().path),

    "identity": #loop($context.identity),

    "stageVariables": #loop($stageVariables),
}
EOF
}
```

results in,

```
'

{
    "enhancedAuthContext": {
    }
,

    "headers": {
    }
,

    "query": {
    }
,

    "path": {
    }
,

    "identity": {
    }
,

    "stageVariables": {
    }
,
}
'
```

### Expected Behavior

The template should be rendered and have the JSON properties.

### How are you starting LocalStack?

Custom (please describe below)

### Steps To Reproduce

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

    docker run localstack/localstack

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

    awslocal s3 mb s3://mybucket


### Environment

```markdown
- OS: MacOS
- LocalStack: 0.14
```


### Anything else?

This example can be used to validate.
https://github.com/localstack/localstack-terraform-samples/tree/master/apigateway-lambda-velocity
elif ("s3:path/" in uri or "s3:action/" in uri) and method == "GET":
            s3 = aws_stack.connect_to_service("s3")
            uri = apply_request_parameters(
                uri,
                integration=integration,
                path_params=path_params,
                query_params=query_string_params,
            )
            uri_match = re.match(TARGET_REGEX_PATH_S3_URI, uri) or re.match(
                TARGET_REGEX_ACTION_S3_URI, uri
            )
            if uri_match:
                bucket, object_key = uri_match.group("bucket", "object")
                LOG.debug("Getting request for bucket %s object %s", bucket, object_key)
                try:
                    object = s3.get_object(Bucket=bucket, Key=object_key)
                except s3.exceptions.NoSuchKey:
                    msg = "Object %s not found" % object_key
                    LOG.debug(msg)
                    return make_error_response(msg, 404)
                headers = aws_stack.mock_aws_request_headers(service="s3")
                if object.get("ContentType"):
                    headers["Content-Type"] = object["ContentType"]
                
                response = request_response_stream(stream=object["Body"], headers=headers)
                return response
            else:
                msg = "Request URI does not match s3 specifications"
                LOG.warning(msg)
                return make_error_response(msg, 400)