fix: Use PublicURL where given

[corrideat]

Related issue

#2422

Proposed changes

Use urls.self.public where possible and given, falling back to urls.self.issuer. Well-known URLs are continue to use urls.self.issuer.

Checklist

• I have read the contributing guidelines.
• I have read the security policy.
• I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security. vulnerability, I
  confirm that I got green light (please contact
  security@ory.sh) from the maintainers to push
  the changes.
• I have added tests that prove my fix is effective or that my feature
  works.
• I have added or changed the documentation.

Further comments

[aeneasr]

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