Integrate Google OAuth 2

[tvprasad]

Hi there,
I intend to incorporate Google OAuth 2 as one of the options to enable support for multiple authentication providers, allowing only one active authentication method at any given time.
I've observed that FSH currently supports AzureAD and JWT. I've come across some articles discussing this topic, particularly in combination with IdentityServer. Would you be able to help me with implementing OAuth2 integration? I would greatly appreciate your guidance.

cc: @fretje / @mluepkes / @MikaelHild / @xlogex