Summary:
public
This diff adds infra to both the Packager and the running app to have a WebSocket based connection between them. This connection is toggled by a new dev menu item, namely `Enable/Disable Hot Loading`.
Reviewed By: vjeux
Differential Revision: D2787621
fb-gh-sync-id: d1dee769348e4830c28782e7b650d025f2b3a786
