MCR-3248 remove Xalan stylesheets and extensions

[yagee-de]

Link to jira.

Moved code to https://github.com/MyCoRe-Org/xalan-legacy-module

This pull request includes significant changes to the mycore-acl and mycore-base modules, focusing on removing unused XSL files, updating stylesheet paths, and improving documentation. The most important changes involve the deletion of obsolete XSL files, adjustments to file paths for consistency, and updates to Java documentation.

Removal of unused XSL files:

• Removed multiple obsolete XSL files from mycore-base/src/main/resources/xsl, including MyCoReLayout.xsl, MyCoReWebPage.xsl, asParent.xsl, copynodes.xsl, i18n-transformation-step.xsl, mycorederivate-versions.xsl, mycoreobject-searchfields.xsl, results-commandlinequery.xsl, save-classification.xsl, and save-derivate.xsl. These files were no longer in use and were cluttering the codebase. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]

Updates to stylesheet paths:

• Updated paths in mycore-acl/src/main/resources/xslt/save-accesskey-derivate.xsl and mycore-acl/src/main/resources/xslt/save-accesskey-object.xsl to use the xslt directory instead of xsl. This ensures consistency with the current directory structure. [1] [2]
• Adjusted stylesheet paths in mycore-base/src/main/resources/config/mycore.properties for stylesheets-yed and normalize-namespace transformers to use the xslt directory. [1] [2]

Documentation improvements:

• Enhanced the Java documentation in mycore-base/src/main/java/org/mycore/frontend/MCRLayoutUtilities.java to better describe the utility methods provided by the class, focusing on access verification and navigation handling.