ENH: Add a method to find all of the names for the loaded data

Author: bnmajor

itkwidgets/viewer.py

@@ -522,6 +522,10 @@ def set_layer_visibility(self, visible: bool, name: str):
     async def get_layer_visibility(self, name: str):
         return await self.viewer_rpc.itk_viewer.getLayerVisibility(name)
 
+    @fetch_value
+    def get_loaded_image_names(self):
+        return list(self.stores.keys())
+
     @fetch_value
     def add_point_set(self, pointSet: PointSet):
         pointSet = _get_viewer_point_set(pointSet)