remove window dependency

Summary:
Fixes required to be able to run Flipper in node.js:
* Adds checks if the `window`-object exists before using it, to allow running in node.
* Imports from within Flipper should directly reference the file they are requiring instead of `import from 'flipper'`. This was done in most of the places. Fixed a few occurrences where this wasn't the case. This is to prevent cyclic dependencies in node.
* shared packages (React, ReactDOM and Flipper) were exposed on the `window` before, changed this to `global` as this works in browser and node.
* Adds some missing methods to our electron stubs (used for testing and headless Flipper)

Reviewed By: passy

Differential Revision: D13786577

fbshipit-source-id: 145d560f1446e7d0bdec2acd8dd54dae983d7b36

src/ui/components/Interactive.js

@@ -13,7 +13,7 @@ import {
   maybeSnapTop,
   SNAP_SIZE,
 } from '../../utils/snap.js';
-import {styled} from '../../ui';
+import styled from '../styled/index.js';
 
 const invariant = require('invariant');
 const React = require('react');

src/ui/components/data-inspector/DataDescription.js

@@ -4,7 +4,7 @@
  * LICENSE file in the root directory of this source tree.
  * @format
  */
-import {Link} from 'flipper';
+import Link from '../Link';
 import type {DataInspectorSetValue} from './DataInspector.js';
 import {PureComponent} from 'react';
 import styled from '../../styled/index.js';

src/ui/components/elements-inspector/sidebar.js

@@ -13,7 +13,7 @@ import Panel from '../Panel.js';
 import ManagedDataInspector from '../data-inspector/ManagedDataInspector.js';
 import {Component} from 'react';
 import {Console} from '../console';
-import {GK} from 'flipper';
+import GK from '../../../fb-stubs/GK';
 
 const deepEqual = require('deep-equal');