Move app/src (mostly) to flipper-ui-core/src

Summary:
This diff moves all UI code from app/src to app/flipper-ui-core. That is now slightly too much (e.g. node deps are not removed yet), but from here it should be easier to move things out again, as I don't want this diff to be open for too long to avoid too much merge conflicts.

* But at least flipper-ui-core is Electron free :)
* Killed all cross module imports as well, as they where now even more in the way
* Some unit test needed some changes, most not too big (but emotion hashes got renumbered in the snapshots, feel free to ignore that)
* Found some files that were actually meaningless (tsconfig in plugins, WatchTools files, that start generating compile errors, removed those

Follow up work:
* make flipper-ui-core configurable, and wire up flipper-server-core in Electron instead of here
* remove node deps (aigoncharov)
* figure out correct place to load GKs, plugins, make intern requests etc., and move to the correct module
* clean up deps

Reviewed By: aigoncharov

Differential Revision: D32427722

fbshipit-source-id: 14fe92e1ceb15b9dcf7bece367c8ab92df927a70

desktop/flipper-ui-core/src/chrome/ShareSheetPendingDialog.tsx

@@ -0,0 +1,44 @@
+/**
+ * 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
+ */
+
+import {Button, Typography} from 'antd';
+import {Layout, Spinner} from 'flipper-plugin';
+import React from 'react';
+
+const {Text} = Typography;
+
+export default function (props: {
+  statusMessage: string;
+  statusUpdate: string | null;
+  hideNavButtons?: boolean;
+  onCancel?: () => void;
+  width?: number;
+}) {
+  return (
+    <Layout.Container style={{width: props.width, textAlign: 'center'}}>
+      <Spinner size={30} />
+      {props.statusUpdate && props.statusUpdate.length > 0 ? (
+        <Text strong>{props.statusUpdate}</Text>
+      ) : (
+        <Text strong>{props.statusMessage}</Text>
+      )}
+      {!props.hideNavButtons && props.onCancel && (
+        <Layout.Right>
+          <div />
+          <Button
+            onClick={() => {
+              props.onCancel && props.onCancel();
+            }}>
+            Cancel
+          </Button>
+        </Layout.Right>
+      )}
+    </Layout.Container>
+  );
+}