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/isPluginVersionMoreRecent.tsx

@@ -0,0 +1,47 @@
+/**
+ * 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 {ConcretePluginDetails} from 'flipper-plugin-lib';
+import semver from 'semver';
+import isPluginCompatible from './isPluginCompatible';
+
+export function isPluginVersionMoreRecent(
+  versionDetails: ConcretePluginDetails,
+  otherVersionDetails: ConcretePluginDetails,
+) {
+  const isPlugin1Compatible = isPluginCompatible(versionDetails);
+  const isPlugin2Compatible = isPluginCompatible(otherVersionDetails);
+
+  // prefer compatible plugins
+  if (isPlugin1Compatible && !isPlugin2Compatible) return true;
+  if (!isPlugin1Compatible && isPlugin2Compatible) return false;
+
+  // prefer plugins with greater version
+  if (semver.gt(versionDetails.version, otherVersionDetails.version)) {
+    return true;
+  }
+  if (
+    semver.eq(versionDetails.version, otherVersionDetails.version) &&
+    versionDetails.isBundled
+  ) {
+    // prefer bundled versions
+    return true;
+  }
+  if (
+    semver.eq(versionDetails.version, otherVersionDetails.version) &&
+    versionDetails.isActivatable &&
+    !otherVersionDetails.isActivatable
+  ) {
+    // prefer locally available versions to the versions available remotely on marketplace
+    return true;
+  }
+  return false;
+}
+
+export default isPluginVersionMoreRecent;