feat: add “provider id” parameter to kratos session

[splaunov]

It is important to know which provider was used for authentication with OIDC. This information might be used for authorisation decisions where corporate customers are using OIDC-based SSO for access to Kratos-protected system.
This PR adds OIDC provider id into session structure.

Related issue(s)

Checklist

• [ x] I have read the contributing guidelines.
• I have referenced an issue containing the design document if my change
  introduces a new feature.
• [ x] I am following the
  contributing code guidelines.
• [x ] I have read the security policy.
• [ x] I confirm that this pull request does not address a security
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• [x ] I have added tests that prove my fix is effective or that my feature
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• I have added or changed the documentation.

Further Comments

[aeneasr]

Awesome, thank you! 🎉 Your contribution makes Ory better :)

[aeneasr]

Fixed the merge conflicts and pushed to #3292 because I don't have write access to this fork