Adds loading indicator when waiting for IGC options (#1302)

* Adds loading indicator when waiting for IGC options

* when editting source text, don't show loading indicator

---------

Co-authored-by: ggurdin <ggurdin@gmail.com>

lib/pangea/choreographer/widgets/it_bar.dart

@@ -393,9 +393,15 @@ class ITChoices extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     try {
-      if (controller.isEditingSourceText || controller.currentITStep == null) {
+      if (controller.isEditingSourceText) {
         return const SizedBox();
       }
+      if (controller.currentITStep == null) {
+        return CircularProgressIndicator(
+          strokeWidth: 2.0,
+          color: Theme.of(context).colorScheme.primary,
+        );
+      }
       return ChoicesArray(
         isLoading: controller.isLoading ||
             controller.choreographer.isFetching ||