Summary:
This diff adds a status bar, which can be used to show the status messages, for example for Litho Support Form.
The logic for the status bar is as follows:
It maintains the array of the messages. At any point it shows the last pushed message. It will keep showing that message until it is being removed, once removed it will show second last message. The messages will be removed as and when its corresponding task/Promise is fulfilled.
Reviewed By: danielbuechele
Differential Revision: D17551495
fbshipit-source-id: 96b2f401599b9ee8a472607e6a2f027e63b3b807
