Minor OIDC devui updates

[sberyozkin]

Minor updates to the DevUI after testing it with Auth0:

• DevUI script should include openid scope if it is not explicitly configured, example, with quarkus.oidc.authentication.scopes=profile. It has always been the case with the Quarkus OIDC itself, but in DevUI it is not currently done. I've found out about it after successfully testing a Quarkus OIDC endpoint with quarkus.oidc.authentication.scopes=profile and then spending a couple of hours trying to figure why in DevUI SPA, IdToken is not returned from Auth0 - turned out the openid scope was missing - it can be easily fixed with quarkus.oidc.authentication.scopes=openid,profile but users should not spend time chasing it if they omit openid
• For redirect from OIDC providers back to DevUI SPA to work, in many case users would have to register a DevUI page address in the provider's console. The currently documented address has changed so I fixed it in the docs. (it works with the default Keycloak devservice launch because a wildcard redirect is enabled)

[github-actions]

🙈 The PR is closed and the preview is expired.

[quarkus-bot]

✔️ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.