DBT-397 update to MyCoRe/MIR 2025.12.x

[yagee-de]

copy legacy code from MyCoRe/MIR 2025.06.x branch here that is deleted now

This pull request introduces several enhancements and fixes across the codebase, focusing on improving access key event handling, updating dependency and plugin configurations, and refining object retrieval and event processing logic. The most notable change is the addition of a new event handler for managing access keys, along with several dependency and code updates to support and streamline related functionality.

Access Key Management Enhancements:

• Added a new class MCRAccessKeyEventHandler to handle creation, update, and deletion events for objects and derivates, ensuring proper import and cleanup of access keys associated with MyCoRe entities.

Build and Dependency Updates:

• Updated the MyCoRe version in pom.xml from 2025.06.1-SNAPSHOT to 2025.12.0-SNAPSHOT and added the mycore-junit4 test dependency. [1] [2]
• Introduced configuration for the maven-compiler-plugin to show deprecation and warning messages during test compilation, with a note to migrate from JUnit4 to JUnit5 in the future.

Object Retrieval and Event Handling Improvements:

• Changed object retrieval in RepairCommands.setMainFile() to use MCRExpandedObject instead of MCRObject, aligning with updated data model usage.
• In MigrationCommands.repairDerivate, removed the logic that added enriched derivate links to metadata, simplifying the repair process.

General Code Quality and Bug Fixes:

• Updated email retrieval in Attendee to use getEMail() instead of the deprecated getEMailAddress().
• Fixed author name encoding in DerivateServletFilter and simplified redirect logic by removing unnecessary checks for empty URLs. [1] [2]
• Updated object ID retrieval in both DerivateServletFilter and VideoSourceResource to remove the use of timeouts, using the simpler method signature. [1] [2]

Dependency and Import Cleanups:

• Added missing import for MCRExpandedObject in RepairCommands.java.

These changes collectively improve the maintainability, reliability, and clarity of the codebase, especially around access key management and build processes.