Separate the concepts of archived and disconnected devices

Summary:
Minor code cleanup to avoid future confusion:

- archived: a device that was imported from a Flipper trace, and only has persisted state
- (dis)connected: a real stateful device that might or might not have an active connection

Reviewed By: nikoant

Differential Revision: D26275459

fbshipit-source-id: eba554b37c39711e367c3795ff4456329a303c22

desktop/app/src/utils/pluginUtils.tsx

@@ -301,7 +301,7 @@ function getFavoritePlugins(
   starredPlugins: undefined | string[],
   returnFavoredPlugins: boolean, // if false, unfavoried plugins are returned
 ): PluginDefinition[] {
-  if (device instanceof ArchivedDevice) {
+  if (device.isArchived) {
     if (!returnFavoredPlugins) {
       return [];
     }