### 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
value = [] if target is None else [target]
                    common.assign_to_path(subject, path, value=value, delimiter="/")
                target = common.extract_from_jsonpointer_path(subject, path)
                if isinstance(target, list) and not path.endswith("/-"):
                    
                    
                    operation["path"] = "%s/-" % path
            result = apply_patch(subject, [operation], in_place=in_place)
            if not in_place:
                subject = result
            results.append(result)
        except JsonPointerException:
            pass  
        except Exception as e:
            if "non-existent object" in str(e):
                if operation["op"] == "replace":
                    
                    operation["op"] = "add"
                    result = apply_patch(subject, [operation], in_place=in_place)
                    results.append(result)
                    continue
                if operation["op"] == "remove" and isinstance(subject, dict):
                    result = subject.pop(operation["path"], None)
                    results.append(result)
                    continue
            raise
    if return_list:
        return results
    return (results or [subject])[-1]
def import_api_from_openapi_spec(