### 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
resources_list = client.get_resources(restApiId=api_id)
    root_res_id = resources_list["items"][0]["id"]
    
    for path, methods in resources.items():
        
        parent_id = root_res_id
        for path_part in path.split("/"):
            api_resource = client.create_resource(
                restApiId=api_id, parentId=parent_id, pathPart=path_part
            )
            parent_id = api_resource["id"]
        
        for method in methods:
            kwargs = {"authorizerId": auth_id} if auth_id else {}
            client.put_method(
                restApiId=api_id,
                resourceId=api_resource["id"],
                httpMethod=method["httpMethod"],
                authorizationType=method.get("authorizationType") or "NONE",
                apiKeyRequired=method.get("apiKeyRequired") or False,
                requestParameters=method.get("requestParameters") or {},
                requestModels=method.get("requestModels") or {},
                **kwargs,
            )
            
            integrations = method["integrations"]
            create_api_gateway_integrations(
                api_id,
                api_resource["id"],
                method,