When creating a new account using the register endpoint, the backend straight up refuses an email field and re-uses the username for it instead. Proposed solution: - Use [UserCreate](https://github.com/ProjNull/MemoPad/blob/82231aaf785e736908717d39dde624a5c7e158ad/backend/src/main/java/eu/projnull/memopad/controllers/dto/UserCreate.java) instead of [LoginCredentials](https://github.com/ProjNull/MemoPad/blob/82231aaf785e736908717d39dde624a5c7e158ad/backend/src/main/java/eu/projnull/memopad/controllers/dto/LoginCredentials.java) in [UserController::register](https://github.com/ProjNull/MemoPad/blob/82231aaf785e736908717d39dde624a5c7e158ad/backend/src/main/java/eu/projnull/memopad/controllers/UserController.java#L39)
When creating a new account using the register endpoint, the backend straight up refuses an email field and re-uses the username for it instead.
Proposed solution: