### 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
"""Extract API ID 'id123' from URLs like https://id123.execute-api.localhost.localstack.cloud:4566"""
    match = re.match(HOST_REGEX_EXECUTE_API, hostname)
    api_id = match.group(1)
    return api_id
def invoke_rest_api_from_request(invocation_context: ApiInvocationContext):
    set_api_id_stage_invocation_path(invocation_context)
    try:
        return invoke_rest_api(invocation_context)
    except AuthorizationError as e:
        api_id = invocation_context.api_id
        return make_error_response("Not authorized to invoke REST API %s: %s" % (api_id, e), 403)
def invoke_rest_api(invocation_context: ApiInvocationContext):
    invocation_path = invocation_context.path_with_query_string
    raw_path = invocation_context.path or invocation_path
    method = invocation_context.method
    headers = invocation_context.headers
    
    authorize_invocation(invocation_context)
    extracted_path, resource = get_target_resource_details(invocation_context)
    if not resource:
        return make_error_response("Unable to find path %s" % invocation_context.path, 404)
    
    validator = RequestValidator(invocation_context, aws_stack.connect_to_service("apigateway"))
    if not validator.is_request_valid():
        return make_error_response("Invalid request body", 400)
    api_key_required = resource.get("resourceMethods", {}).get(method, {}).get("apiKeyRequired")