feature request: mandatory or default value for user field

[x-zx]

What problem did you meet?

When users register, the name field is sometimes left blank, which can lead to exceptions or errors in the software that requires this field to be filled.

Describe what you'd like Logto to have

I would like Logto to implement a mechanism that either enforces the name field to be mandatory during registration or automatically assigns a default value if left blank. This could help prevent errors related to missing user information and improve the overall user registration experience.