Added progress messages and quick access to exported files (#1112)

app/MindWork AI Studio/Tools/DataFileExportRunningMessage.cs

@@ -0,0 +1,32 @@
+using AIStudio.Components;
+
+namespace AIStudio.Tools;
+
+/// <summary>
+/// The notification that a file is being exported.
+/// </summary>
+/// <remarks>
+/// It stays until the export ends, however long that takes, since a timeout would claim an end which
+/// has not happened. Closing it is allowed: the export goes on all the same.
+/// </remarks>
+/// <param name="Key">The key of the export, shared with its success notification, which replaces this one.</param>
+/// <param name="FilePath">The file the export writes.</param>
+public readonly record struct DataFileExportRunningMessage(string Key, string FilePath)
+{
+    public void Show(ISnackbar snackbar)
+    {
+        var parameters = new Dictionary<string, object>
+        {
+            [nameof(FileExportRunningMessage.FileName)] = Path.GetFileName(this.FilePath)
+        };
+
+        snackbar.Add<FileExportRunningMessage>(parameters, Severity.Info, config =>
+        {
+            config.HideIcon = true;
+            config.RequireInteraction = true;
+            config.HideTransitionDuration = 600;
+        }, this.Key);
+    }
+
+    public void Hide(ISnackbar snackbar) => snackbar.RemoveByKey(this.Key);
+}