Scaffolding FlipperKitBloksDebuggerPlugin

Summary:
Add scaffolding for the bloks-debugger plugin (Flipper, iOS).
On iOS side, integrate with fbios, igios, msgios & FBBloksShell playground apps.

Reviewed By: aigoncharov

Differential Revision: D43306472

fbshipit-source-id: ffc6348d6e0810d4ddeebe3b192b7bf06049a2d1

desktop/static/icons.json

@@ -664,5 +664,8 @@
   ],
   "app-horizon-assets": [
     16
+  ],
+  "app-bloks": [
+    16
   ]
-}
+}