Implement Diff selection flow in UIQR Flipper Plugin

Summary: Allow the user to manually select a diff from a list of diffs they have authored to send a screen to. This is particularly useful for NT users.

Reviewed By: nscoding

Differential Revision: D27804191

fbshipit-source-id: 805923399f2ced8d9c3b3ca0c80d5cdfd63af4f8

desktop/static/icons.json

@@ -586,5 +586,8 @@
   ],
   "box-outline": [
     24
+  ],
+  "differential": [
+    16
   ]
 }