Added a way to read what the AI received from your sources (#1100)

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

app/MindWork AI Studio/Chat/SetFileAttachmentExtensions.cs

@@ -0,0 +1,21 @@
+namespace AIStudio.Chat;
+
+public static class SetFileAttachmentExtensions
+{
+    /// <summary>
+    /// Attaches a file in place of the attachment of the same file the set held before.
+    /// </summary>
+    /// <remarks>
+    /// The attachments differ by more than their files: one of a message being edited holds the
+    /// entry of the text it was sent with, and the size of the file may have changed since. Both
+    /// would stay in the set, and the message would go with the old and the new text of the file.
+    /// Attaching a file again means the file as it is now.
+    /// </remarks>
+    /// <param name="attachments">The attachments of a message.</param>
+    /// <param name="attachment">The attachment of the file just attached.</param>
+    public static void AttachInPlaceOfSameFile(this HashSet<FileAttachment> attachments, FileAttachment attachment)
+    {
+        attachments.RemoveWhere(existing => string.Equals(existing.FilePath, attachment.FilePath, StringComparison.Ordinal));
+        attachments.Add(attachment);
+    }
+}