### 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
PATH_REGEX_RESPONSES = r"^/restapis/([A-Za-z0-9_\-]+)/gatewayresponses(/[A-Za-z0-9_\-]+)?(\?.*)?"
PATH_REGEX_DOC_PARTS = r"^/restapis/([A-Za-z0-9_\-]+)/documentation/parts/?([^?/]+)?(\?.*)?"
PATH_REGEX_PATH_MAPPINGS = r"/domainnames/([^/]+)/basepathmappings/?(.*)"
PATH_REGEX_CLIENT_CERTS = r"/clientcertificates/?([^/]+)?$"
PATH_REGEX_VPC_LINKS = r"/vpclinks/([^/]+)?(.*)"
PATH_REGEX_TEST_INVOKE_API = r"^\/restapis\/([A-Za-z0-9_\-]+)\/resources\/([A-Za-z0-9_\-]+)\/methods\/([A-Za-z0-9_\-]+)/?(\?.*)?"
APIGATEWAY_SQS_DATA_INBOUND_TEMPLATE = (
    "Action=SendMessage&MessageBody=$util.base64Encode($input.json('$'))"
)
TAG_KEY_CUSTOM_ID = "_custom_id_"
API_REGIONS = {}
class APIGatewayRegion(RegionBackend):
    
    
    authorizers: Dict[str, List[Dict]]
    
    validators: Dict[str, List[Dict]]
    
    documentation_parts: Dict[str, List[Dict]]
    
    gateway_responses: Dict[str, List[Dict]]
    
    account: Dict[str, Any]
    
    base_path_mappings: Dict[str, List[Dict]]
    
    vpc_links: Dict[str, Dict]
    
    client_certificates: Dict[str, Dict]
    def __init__(self):