Added a common augmentation interface & default implementation (#288)

app/MindWork AI Studio/Chat/IImageSource.cs

@@ -0,0 +1,17 @@
+namespace AIStudio.Chat;
+
+public interface IImageSource
+{
+    /// <summary>
+    /// The type of the image source.
+    /// </summary>
+    /// <remarks>
+    /// Is the image source a URL, a local file path, a base64 string, etc.?
+    /// </remarks>
+    public ContentImageSource SourceType { get; init; }
+
+    /// <summary>
+    /// The image source.
+    /// </summary>
+    public string Source { get; set; }
+}