Previously, when creating a new event type, user was still allowed to create a new event type, even if the event length's field was empty. This would cause a prisma error, since it would receive NaN and no event would have been added, but the page still reloaded. Therefore, a very basic validation to address this, at least in the short-term.
- Due to the lack of router object, after clicking "Update" on the Event Type - a response would be printed to the console, but without being routed back to the availability page.