Empty string in cookie value 400s

Just discovered that if you provide an *empty string value* for a *cookie* during a *POST* the server errors and says:

```
2020-08-10T13:19:43.083Z - warn: [error-logger.js] {"status":400,"statusText":"Bad Request","errors":[{"field":[],"location":"body","messages":["\"value\" must be a string"],"types":["string.base"]},{"field":["cookies}
```

This error is incredibly vague and also incorrect. For some reason an empty string is being interpreted as undefined and/or null. Took me a while to realize that if `value` is `''` then we need to remove the cookie from the POST.