make thumbnail generating multithread

fix the bug with open video
add class distribution chart

Azaion.Annotator.Test/ParallelExtTest.cs

@@ -0,0 +1,46 @@
+using System.Diagnostics;
+using Azaion.Annotator.Extensions;
+using FluentAssertions;
+using Xunit;
+using ParallelOptions = Azaion.Annotator.Extensions.ParallelOptions;
+
+namespace Azaion.Annotator.Test;
+
+public class ParallelExtTest
+{
+    [Fact]
+    public async Task ParallelExtWorksOkTest()
+    {
+        var list = Enumerable.Range(0, 10).ToList();
+
+        var sw = Stopwatch.StartNew();
+        await ParallelExt.ForEachAsync(list, async (i, cancellationToken) =>
+        {
+            await Task.Delay(TimeSpan.FromSeconds(i), cancellationToken);
+        }, new ParallelOptions
+        {
+            CpuUtilPercent = 100,
+            ProgressUpdateInterval = 1
+        });
+
+        var elapsed = sw.Elapsed;
+        elapsed.Should().BeLessThan(TimeSpan.FromSeconds(11));
+    }
+
+    [Fact]
+    public async Task ParallelLibWorksOkTest()
+    {
+        var list = Enumerable.Range(0, 10).ToList();
+
+        var sw = Stopwatch.StartNew();
+        await Parallel.ForEachAsync(list, new System.Threading.Tasks.ParallelOptions
+        {
+            MaxDegreeOfParallelism = Environment.ProcessorCount,
+        }, async (i, cancellationToken) =>
+        {
+            await Task.Delay(TimeSpan.FromSeconds(i), cancellationToken);
+        });
+        var elapsed = sw.Elapsed;
+        elapsed.Should().BeLessThan(TimeSpan.FromSeconds(11));
+    }
+}