Introduce GitHub OAuth Authentication

[peregrineshahin]

This implements the long waited GitHub Auth

Allows 3 options:

1- Registering with GitHub
2- Linking your existing profile with GitHub
3- Logging in with GitHub

Instructions

• Hide Sensitive Variables: Ensure GITHUB_CLIENT_ID and GITHUB_CLIENT_SECRET are hidden in the configuration file.

• Generate GitHub OAuth Keys:

  1. Go to GitHub OAuth Application Settings.
  2. Create a new OAuth application with the following details:
     • Application Name: Fishtest
     • Homepage URL: https://tests.stockfishchess.org/
     • Authorization Callback URL: https://tests.stockfishchess.org/github/callback

• Update Configuration: Replace GITHUB_CLIENT_ID and GITHUB_CLIENT_SECRET placeholders with the generated keys from GitHub.

Note: this PR only concerns the Web part. I will make it happen for workers after most of the PRs gets resolved, in a final effort to get rid of the most serious issue in the framework which is the usage of plain text passwords.

Preview:

[vondele]

@peregrineshahin that kind of comment is not appreciated.