Manual selection of authentication method

[Marco Naimoli]

Hi, my IDP (3.2.1) installation uses Password authentication; I've added
a RemoteUser authentication (and it works), but the final user cannot
choose what authentication method to use, IDP chooses, based on
general-auth.xml file.
I'd like to have a simple login page with user/password and a "link" (or
something similar) for the RemoteUser auth; and, in general, I'd like
to know if it's possible to create a page where a user can choose among
all authentication methods supported. I've read documentation about MCB,
but it's seems related to MFA, while I just use simple authentication.
Any help will be appreciated
Thank you
Marco