Aggregate all ScenarioRunResult from a scenario

[verdie-g]

I'm developing data-driven evaluations using Langfuse (see #6860) that looks like this

public class SimpleQuestionsScenario
{
    private static readonly ReportingConfiguration ReportingConfiguration = LangfuseReportingConfiguration.Create(/* ... */);

    [TestCaseSource(nameof(DownloadDataset))]
    public async Task Evaluate(DatasetItem item)
    {
        await using var scenarioRun = await ReportingConfiguration.CreateScenarioRunAsync(
            scenarioName: DatasetName,
            iterationName: item.Id!,
            additionalTags: []);

        var response = /* ... */

        EvaluationResult result = await scenarioRun.EvaluateAsync(messages, response, [new TraceIdContext(traceId)]);
    }

I realized that IEvaluationResultStore.WriteResultsAsync is always called with a single ScenarioRunResult in the ScenarioRun.DisposeAsync.

I would like to score an entire Langfuse dataset run (MEAI execution), meaning have a callback when all my iterations are ran that has access to all the ScenarioRunResult. Is there a concept like this in MEAI?