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/AssistantBuilderAssistantMetadata.cs

@@ -0,0 +1,12 @@
+namespace AIStudio.Assistants.Builder;
+
+internal sealed class AssistantBuilderAssistantMetadata
+{
+    public string Kind { get; init; } = string.Empty;
+    public string Title { get; init; } = string.Empty;
+    public string Description { get; init; } = string.Empty;
+    public string? SystemPrompt { get; init; }
+    public string? SubmitText { get; init; }
+    public bool? AllowAiStudioProfiles { get; init; }
+    public AssistantBuilderChatLaunchMetadata? Launch { get; init; }
+}