Improved the dialogs for local data sources and the Batch Processing assistant (#1096)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/Tests/Tools/LongExtensionsTests.cs

@@ -0,0 +1,25 @@
+using System.Globalization;
+
+using AIStudio.Tools;
+
+namespace AIStudio.Tests.Tools;
+
+public sealed class LongExtensionsTests
+{
+    [TestCase(0L, "0 B")]
+    [TestCase(1_023L, "1023 B")]
+    [TestCase(1_536L, "1.5 kB")]
+    [TestCase(1_992_294L, "1.9 MB")]
+    [TestCase(1_073_741_824L, "1 GB")]
+    [TestCase(1_572_864_000L, "1.46 GB")]
+    public void FileSizesKeepTheirFraction(long sizeBytes, string expected)
+    {
+        Assert.That(sizeBytes.FileSize(CultureInfo.InvariantCulture), Is.EqualTo(expected));
+    }
+
+    [Test]
+    public void FileSizesUseTheDecimalSeparatorOfTheCulture()
+    {
+        Assert.That(1_992_294L.FileSize(CultureInfo.GetCultureInfo("de-DE")), Is.EqualTo("1,9 MB"));
+    }
+}