Rename package to 'flipper'

Summary:
- rename package `'sonar'` > `'flipper'`
- rename package `'sonar-static'` > `'flipper-static'`
- rename package export from `window.Sonar` to `window.Flipper`

Reviewed By: passy

Differential Revision: D9851181

fbshipit-source-id: 34d4447c3b287496b3d20ddb54471ce777ec74e1

src/init.js

@@ -7,7 +7,7 @@
 
 import {Provider} from 'react-redux';
 import ReactDOM from 'react-dom';
-import {ContextMenuProvider} from 'sonar';
+import {ContextMenuProvider} from 'flipper';
 import {precachedIcons} from './utils/icons.js';
 import GK from './fb-stubs/GK.js';
 import Logger from './fb-stubs/Logger.js';