Uncought Exceptions in IOptimizers get lost

[pfleck]

Because the Task of IOptimizer.StartAsync() is not awaited in IOptimizerView.startButton_Click any exception that was not yet handled is lost.

This issue applies to the following

• IOptimizerView.startButton_Click: Content.StartAsync();
• CrossValidation.Start: clonedAlgorithm.StartAsync(cancellationToken);
• CrossValidationView.startButton_Click: Content.StartAsync();
• OKBAlgorithmView.startButton_Click: Content.StartAsync();
• OptimizerTask.Start: Item.StartAsync();
• EngineTask:Start: Item.StartAsync();