### 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
integration = self.integration or {}
        return integration.get("uri") or integration.get("integrationUri")
    @property
    def auth_context(self) -> Optional[Dict]:
        if isinstance(self.auth_info, dict):
            context = self.auth_info.setdefault("context", {})
            principal = self.auth_info.get("principalId")
            if principal:
                context["principalId"] = principal
            return context
    @property
    def auth_identity(self) -> Optional[Dict]:
        if isinstance(self.auth_info, dict):
            if self.auth_info.get("identity") is None:
                self.auth_info["identity"] = {}
            return self.auth_info["identity"]
    def is_websocket_request(self):
        upgrade_header = str(self.headers.get("upgrade") or "")
        return upgrade_header.lower() == "websocket"
    def is_v1(self):
        """Whether this is an API Gateway v1 request"""
        return self.apigw_version == ApiGatewayVersion.V1
    def cookies(self):
        if cookies := self.headers.get("cookie") or "":
            return list(cookies.split(";"))
        return []