Confusion matrix schema alignment

[stavrostheocharis]

Description In schema "PerformanceMetric" there is a misalignment between the BinaryClassificationMetricsPipelineResult and the MultiClassificationMetricsPipelineResult.

In the first one the true_negative, false_positive, etc. are on the outer level. On the other side we have them inside a confusion matrix attribute: confusion_matrix: Dict[str, ConfusionMatrix]

Solution Make them aligned. Add in BinaryClassificationMetricsPipelineResult a new attribute confusion_matrix and include inside the corresponding metrics.

Note: Maybe changes inside other parts of the code may be needed!

[sinnec]

Changes will be needed in run_create_alerts_pipeline as well to match the changed schema.