Move desktop-related code to "desktop" subfolder (#872)

Summary:
Pull Request resolved: https://github.com/facebook/flipper/pull/872
Move all the JS code related to desktop app to "desktop" subfolder.

The structure of "desktop" folder:
- `src` - JS code of Flipper desktop app executing in Electron Renderer (Chrome) process. This folder also contains all the Flipper plugins in subfolder "src/plugins".
- `static` - JS code of Flipper desktop app bootstrapping executing in Electron Main (Node.js) process
- `pkg` - Flipper packaging lib and CLI tool
- `doctor` - Flipper diagnostics lib and CLI tool
- `scripts` - Build scripts for Flipper desktop app
- `headless` - Headless version of Flipper app
- `headless-tests` - Integration tests running agains Flipper headless version

Reviewed By: passy

Differential Revision: D20249304

fbshipit-source-id: 9a51c63b51b92b758a02fc8ebf7d3d116770efe9

desktop/static/transforms/electron-process.js

@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+module.exports = function(babel, options) {
+  return {
+    name: 'change-process-to-electronProcess',
+    visitor: {
+      MemberExpression(path) {
+        if (
+          path.node.object.type === 'Identifier' &&
+          path.node.object.name === 'process' &&
+          !path.scope.hasBinding('process')
+        ) {
+          path.node.object.name = 'electronProcess';
+        } else if (
+          path.node.object.type === 'MemberExpression' &&
+          path.node.object.object.type === 'Identifier' &&
+          path.node.object.object.name === 'global' &&
+          path.node.object.property.type === 'Identifier' &&
+          path.node.object.property.name === 'process'
+        ) {
+          path.node.object.property.name = 'electronProcess';
+        }
+      },
+    },
+  };
+};