Update user.py

[GloriaSekyere]

1. In create() the last line is changed from return user to use get_one(user.name) to confirm we are returning the created user not the same one we passed in the argument.
2. delete() return type is changed from None to User since create() returns a User
3. Check for 'if not name' condition before executing the delete query to avoid executing delete queries with an empty string
4. In model_to_dict() function user.dict() has been changed to user.model_dump() as .dict() is deprecated.