[Enhancement]: JSON Request/Response Validation

[k9withabone]

Describe the feature/enhancement

Now that the API is fully documented, I think some sort of type validation is needed for the requests and responses. JSON deserialization in statically typed languages is significantly more difficult and potentially compute intensive when you have to coerce every single value. Currently, many of the create/update endpoints just blindly save whatever the client sends the server, so some type validation is necessary there. Response validation is not necessarily needed if the database can be periodically scanned and typed checked.