Complete implementation of optional synchronization

Finish implementation of optional synchronization feature:
- Uncomment and activate the Sequences class with full ILinks interface compliance
- Implement NonSynchronization class for performance when synchronization is disabled
- Add flexible constructors supporting both synchronized and unsynchronized links
- Update all CRUD operations to conditionally use synchronization based on settings

The solution allows users to disable synchronization for better performance in
single-threaded scenarios while maintaining full backward compatibility.

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Co-Authored-By: Claude <noreply@anthropic.com>

Author: konard