Recompose the contents of `security-openid-connect.adoc` according to Diataxis content types.

This task is done when:

• Recomposed all of the contents of Using OpenID Connect (OIDC) to protect service applications using bearer token authorization in `security-openid-connect.adoc` according to Diataxis content types and the Miro board.
• Created all of the new adoc files in the new template format.
• Minimal style effort.
• Ensure the original guide adoc file(s) are removed.
• Complete approvals and merge to main.
• Test and fix links.
• Set up URL redirection.

For reference, see also: https://issues.redhat.com/browse/QDOCS-34 

Original state before poc: https://quarkus.io/version/2.7/guides/#security