Length Validation and error handling of adding new user

[ipajen]

Today there is missing validation of max length of First Name, Last Name and Email. If any of the fields are greater than possible value to save in the database WordPress GUI will present:

Result: New user created.

As a User I would except 1. Error message instead of a false message that stats: New user created
and 2. a Max length of input fields in GUI to avoid to send a request.

There are some today. "User URL may not be longer than 100 characters.", and here would be nice if the input field was max 100.