Sign in through Apple and Google

[VadimGush]

For the first version of the server it would be better to not have to worry about all registration and account management process (email verification, bot prevention, password resets and etc.). It would be easier instead to setup login through Google and Apple.

• Apple documentation: https://developer.apple.com/documentation/sign_in_with_apple/displaying_sign_in_with_apple_buttons_on_the_web
• Google documentation: https://developers.google.com/identity/sign-in/web/sign-in

This issue includes both server implementation and web-app support.