### 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
rest_api: apigateway_models.RestAPI, function_id: str, body: Dict, query_params: Dict
) -> apigateway_models.RestAPI:
    """Import an API from an OpenAPI spec document"""
    
    rest_api.resources = {}
    def get_or_create_path(path):
        parts = path.rstrip("/").replace("//", "/").split("/")
        parent_id = ""
        if len(parts) > 1:
            parent_path = "/".join(parts[:-1])
            parent = get_or_create_path(parent_path)
            parent_id = parent.id
        existing = [
            r
            for r in rest_api.resources.values()
            if r.path_part == (parts[-1] or "/") and (r.parent_id or "") == (parent_id or "")
        ]
        if existing:
            return existing[0]
        return add_path(path, parts, parent_id=parent_id)
    def add_path(path, parts, parent_id=""):