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/utils/notifications.tsx

@@ -0,0 +1,43 @@
+/**
+ * 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 {notification, Typography} from 'antd';
+import React from 'react';
+import {FlipperDevTools} from '../chrome/FlipperDevTools';
+import {setStaticView} from '../reducers/connections';
+import {getStore} from '../store';
+import {Layout} from '../ui';
+import {v4 as uuid} from 'uuid';
+
+const {Link} = Typography;
+
+export function showErrorNotification(message: string, description?: string) {
+  const key = uuid();
+  notification.error({
+    key,
+    message,
+    description: (
+      <Layout.Container gap>
+        {description ?? <p>{description}</p>}
+        <p>
+          See{' '}
+          <Link
+            onClick={() => {
+              getStore().dispatch(setStaticView(FlipperDevTools));
+              notification.close(key);
+            }}>
+            logs
+          </Link>{' '}
+          for details.
+        </p>
+      </Layout.Container>
+    ),
+    placement: 'bottomLeft',
+  });
+}