[#1154] Replace legacy ForgeRock relative links in the guides with Antora xrefs

[vharseko]

Fixes #1154

About 30 relative links in the guides pointed to the old ForgeRock documentation layout and resolve to 404 on https://doc.openidentityplatform.org. They now point at the matching pages of this documentation set.

Changes

• link:../../../docs/openam/13/… and link:../../../openam/13/… in the Web and Java EE agent guides → xrefs to the matching Administration / Installation Guide chapters and anchors. Two anchors no longer exist and are mapped to their closest current sections:
  • wildcard-syntax → chap-authz-policy.adoc#policy-patterns-wildcards
  • configure-authz-policy / chap-authz-policy → chap-authz-policy.adoc#configure-policies-with-console
• link:../../../openam-web-policy-agents/… / link:../../../openam-jee-policy-agents/… → xref:../web-users-guide/index.adoc[…] / xref:../jee-users-guide/index.adoc[…]; the #configure-web-policy-agent link goes to web-users-guide/chap-web-agents.adoc.
• link:../../../openam/admin-guide/chap-cdsso → xref:../admin-guide/chap-cdsso.adoc#chap-cdsso[…]. In chap-apache-tomcat.adoc the "Configuring Policies" link also pointed at the CDSSO chapter; it now points at the policy section.
• xref:./chap-jee-agent-config.adoc#… in chap-apache-tomcat.adoc and chap-jetty.adoc → xref:chap-jee-agent-config.adoc#…: AntoraMojo turned the ./ form into xref:.:chap-….

The xrefs use the form already used across the guides, xref:../<guide>/<chapter>.adoc#<id>[…], which AntoraMojo rewrites to xref:<guide>:<chapter>.adoc#<id>[…]. window=\_blank is dropped from these links, since they now stay within the site, and the link texts follow the target headings.

Verification

• No link:../../ or xref:./ links remain in the guide sources.
• All 268 xrefs in the changed files resolve: the target file exists and declares the anchor.
• mvn -P man-pages package in openam-doc-source succeeds; the Antora output contains the rewritten links (e.g. xref:admin-guide:chap-cdsso.adoc#chap-cdsso[), all nine PDFs build, and asciidoctor reports no warnings.

Not in scope: about 20 link:../<guide>/index.html#<anchor> links (dev-guide, reference, jee-users-guide) open the guide's index page on the site rather than the anchored section; they can be handled separately.

[maximthomas]

praise: Every legacy relative link in the guides now stays within this documentation set.

• No link:../../ and no xref:./ remain under openam-documentation/openam-doc-source/src/main/asciidoc at the head.
• The "Configuring Policies" link in jee-users-guide/chap-apache-tomcat.adoc:31, which pointed at the CDSSO chapter, now targets admin-guide/chap-authz-policy.adoc#configure-policies-with-console.