Add display names or full names instead of FHICT names

[MaxKorlaar]

Is your feature request related to a problem? Please describe. When you sign up with your FHICT account, your full name as shown in the FHICT is used, including your initials at the end, and your surname first.

Describe the solution you'd like I'd like my name to be either changeable, an option for a custom display name or that my name is based on my first name + my surname, which the FHICT api offers as well.

Additional context None

[Brend-Smits]

We've changed it to be first name + surname. In the future, we might look into making it changeable