### 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
if not stage:
        return {}
    region_name = [name for name, region in apigateway_backends.items() if api_id in region.apis][0]
    api_gateway_client = aws_stack.connect_to_service("apigateway", region_name=region_name)
    try:
        response = api_gateway_client.get_stage(restApiId=api_id, stageName=stage)
        return response.get("variables")
    except Exception:
        LOG.info(f"Failed to get stage {stage} for api id {api_id}")
        return {}
def get_event_request_context(invocation_context: ApiInvocationContext):
    method = invocation_context.method
    path = invocation_context.path
    headers = invocation_context.headers
    integration_uri = invocation_context.integration_uri
    resource_path = invocation_context.resource_path
    resource_id = invocation_context.resource_id
    set_api_id_stage_invocation_path(invocation_context)
    relative_path, query_string_params = extract_query_string_params(
        path=invocation_context.path_with_query_string
    )
    api_id = invocation_context.api_id
    stage = invocation_context.stage
    source_ip = headers.get("X-Forwarded-For", ",").split(",")[-2].strip()
    integration_uri = integration_uri or ""
    account_id = integration_uri.split(":lambda:path")[-1].split(":function:")[0].split(":")[-1]
    account_id = account_id or TEST_AWS_ACCOUNT_ID
    domain_name = f"{api_id}.execute-api.{LOCALHOST_HOSTNAME}"