Correct confusion matrix calculation-function `evaluate_detection_batch` (#1853)

* Correct confusion matrix calculation-function evaluate_detection_batch
* Correct confusion matrix computation
* Add 3 more tests for empty Detections-GTs
* Minor changes in too-long lines corrected
* Replace deprecated mock_detections with _create_detections
* Fix indentation in test assertions and add missing `self` parameter in `test_confusion_matrix`.
* Update metric computations to improve numerical stability and replace deprecated NumPy functions
* Add IoU+class matching tests and synthetic dataset fixtures for detection metrics
* Use `Optional` for type hinting `classes` parameter in `_yolo_dataset_factory`. Import `Optional` from `typing`.
* Refactor detection metric tests to simplify confusion matrix assertions and enhance IoU+class matching validation.
* Apply suggestions from code review
* fix(pre_commit): 🎨 auto format pre-commit hooks

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>