[FEATURE REQUEST] be able to configure OIDC claim scope

[gpongelli]

Is your feature request related to a problem? Please describe.
To handle discussion about Authelia like this, this or this, it should be useful to configure the OIDC scope as it's done on browser through WEB_OIDC_SCOPE: "openid profile email groups" environment variable.

with custom scopes like opencloud_scope in this discussion I made , it's possible in Authelia to provide the opencloud's default role through an expression, or use the proxy.yaml file to fully customize oidc things.

Describe the solution you'd like

An idea I had, and I was trying to implement on my fork, is to have a text field into settings page where will be possible write a list of OIDC scopes. Those scopes must include the mandatory ones, or otherwise those scopes will be appended to the mandatory ones (maybe it's a safer choice).
I've ended my research when I've reached the class load method where defaults are statically attached to dictionary and I've no idea on how to change that in ObjC.

Describe alternatives you've considered
I've no idea if just adding a custom scope directly into the ios-sdk string can work.
Obviously when used by Authelia it could work, but in other cases I've no idea if it led to errors (no scopes from id provider).

TASKS

• Research (if needed)
• Create branch feature/feature_name
• Development tasks
  • Implement whatever
• Code review and apply changes requested
• Design test plan
• QA
• Merge branch feature/feature_name into main

PR

• App
• Library (if needed)