[#232] Fix legacy relative links and typos in the guides

[vharseko]

Fixes #232

Changes

Paths are relative to openidm-doc/src/main/asciidoc.

• Links to old OpenDJ / OpenAM versions and other products: every link:../../../opendj|openam/… is now a cross-component xref to the current guide and anchor, e.g. xref:opendj:admin-guide:chap-replication.adoc#read-ecl-as-regular-user[…]. AntoraMojo leaves such xrefs unchanged (it only strips ../ and turns / into :). Besides the links listed in the issue, the same kind of link in samples-guide/chap-fullstack-sample.adoc:72 and :130 (openam/13/admin-guide) is fixed too.
  • connectors-guide/chap-ldap.adoc: referential integrity is described in the OpenDJ Directory Server Developer's Guide, not the Administration Guide; the text now says so.
  • integrators-guide/chap-passwords.adoc: the link points to the "LDAP Client Access Over SSL" section instead of the whole guide.
  • window=\_blank is dropped from these links: an xref takes only the link text.
• integrators-guide/appendix-scripting.adoc: the "managed object config object" cell spans 7 trigger rows, not 6. The wrong row span shifted the cells and the last row (onValidate) was dropped.
• connectors-guide/chap-sap.adoc: hhttps → https.
• samples-guide/chap-groovy-samples.adoc: the maven.forgerock.org download lines are removed from the mvn install output.

Verification

The site (doc.openidentityplatform.org, master) was built with Antora before and after, with the changed pages converted the way AntoraMojo does:

• Antora errors 4 → 3: dropping cells from incomplete row detected end of table in appendix-scripting.adoc is gone; no other OpenIDM messages except missing attribute;
• the OpenIDM HTML no longer contains ../../../, hhttps or maven.forgerock;
• all 9 link targets exist in the built site with their anchors;
• the managed.json table now has 9 body rows instead of 8.

Not in this PR

• custom-scripted-connector-bundler/src/main/resources/pom.template still uses org.forgerock.openicf.connectors:connectors-parent:1.5.0.0 from maven.forgerock.org, so the Groovy sample does not build as written. Fixing it is a code change and belongs in a separate issue.
• Once this is merged and published, the OpenIDM#232 entries in .github/build-baseline of the site repository can be removed.