Using 'Name' instead of 'FirstName' and 'LastName'

[HoudaifaBouamine]

For better user experience (UX) we will ask only for the Name of the user.

only the DTO has changed for faster integration with the front end
so for now Name from Dto map to FirstName in the logic and database,
we need to change the backend logic and the database table also to use Name and delete FirstName and LastName