Cannot edit users when using REMOTE_USER and ALB with OIDC

[sam-dumont]

I just installed baby buddy and the REMOTE_USER works fine with Auth0 + ALB OIDC but the user that is created is with the format "auth0|xxxx(24 chars)".

This works for login and logout but when I try to edit the user to grant extra permissions the validation is not happy because there's a '|' character in the username.

I could fix it by editing the db directly but it would be more convenient if it was possible from the UI

[cdubz]

Huh yeah apparently the username can only have the special characters @.+-_. I'm not sure where this requirement comes from but we'd need to figure that out and understand if there are any security implications to supporting this. Happy to review PRs to address!