[Feature Request] SSO username remap to different OIDC attributes

[tbfpartner]

Is your feature request related to a problem? Please describe.
When using the SSO feature, newly registered users currently get the first name (from/through the OIDC Provider) as a username in TRMM. In larger organizations, this quickly can become a problem.
Current workaround: renaming them manually.

Describe the solution you'd like
Make it possible to define, which OIDC-Provider-Field (attribute) is mapped to the username.

This feature request could also be extended to other fields or ultimatively, to the role assignment being mapped to "oidc provided groups". But this isnt actually part of this feature request - more an idea for the far future.