Added direct-chat launchers for assistant plugins and a dialog to reconfigure them (#935)

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

app/MindWork AI Studio/Assistants/Builder/AssistantBuilderPluginMetadata.cs

@@ -0,0 +1,8 @@
+namespace AIStudio.Assistants.Builder;
+
+internal sealed class AssistantBuilderPluginMetadata
+{
+    public string Name { get; init; } = string.Empty;
+    public string Description { get; init; } = string.Empty;
+    public string[] Categories { get; init; } = [];
+}