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/chrome/MainSidebar.js

@@ -22,7 +22,7 @@ import {
   Text,
   Glyph,
   styled,
-} from 'sonar';
+} from 'flipper';
 import React from 'react';
 import {devicePlugins} from '../device-plugins/index.js';
 import plugins from '../plugins/index.js';