[Feature]: Add support for Custom OAuth Providers

[ajsokolik]

What do you imagine 💭

Add support for custom OAuth providers (Authentik, Authelia, Keycloak, etc). Ideally it'll just need name, client ID, secret, and issuer or configuration URL (if unable to pull the config URL based on issuer)

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[KSJaay]

Yeah, this is already somewhat implemented but I need to setup instances of Autehntik, Authelia, and Keycloak to make sure it works as expected for all services.

[ajsokolik]

Yeah, ideally you should just be able to parse the configuration URL (usually something like https://idprovider.example.com/whatever/.well-known/openid-configuration) and along with a client ID and secret we should have everything we need. That should cover all the standard Identity Providers out there as that's the OIDC standard.

[KSJaay]

Yeah that's the thought, I'd expect the person to provide a configuration, client id, and secret. But, I actually only found out about OIDC recently so I need to learn a bit more about how OIDC works to implement it properly.

[KSJaay]

As of #179 custom OAuth/OIDC platforms should now be supported. Going to close this issue, if you have any issues please let me know and I'll fix those as soon as possible.