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/fb-stubs/IDEFileResolver.tsx

@@ -0,0 +1,72 @@
+/**
+ * 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 {ElementFramework} from '../ui/components/elements-inspector/ElementFramework';
+import {ElementsInspectorElement} from 'flipper-plugin';
+
+export enum IDEType {
+  'DIFFUSION',
+  'AS',
+  'XCODE',
+  'VSCODE',
+}
+
+export abstract class IDEFileResolver {
+  static async resolveFullPathsFromMyles(
+    _fileName: string,
+    _dirRoot: string,
+  ): Promise<string[]> {
+    throw new Error('Method not implemented.');
+  }
+
+  static openInIDE(
+    _filePath: string,
+    _ide: IDEType,
+    _repo: string,
+    _lineNumber = 0,
+  ) {
+    throw new Error('Method not implemented.');
+  }
+
+  static async getLithoComponentPath(_className: string): Promise<string> {
+    throw new Error('Method not implemented.');
+  }
+
+  static async getCKComponentPath(_className: string): Promise<string> {
+    throw new Error('Method not implemented.');
+  }
+
+  static getBestPath(
+    _paths: string[],
+    _className: string,
+    _extension?: string,
+  ): string {
+    throw new Error('Method not implemented.');
+  }
+
+  static async resolvePath(
+    _className: string,
+    _framework: string,
+  ): Promise<string> {
+    throw new Error('Method not implemented.');
+  }
+
+  static isElementFromFramework(
+    _node: ElementsInspectorElement,
+    _framework: ElementFramework,
+  ): boolean {
+    throw new Error('Method not implemented.');
+  }
+
+  static isElementFromSupportedFramework(
+    _node: ElementsInspectorElement,
+  ): boolean {
+    throw new Error('Method not implemented.');
+  }
+}