Yarn workspaces

Summary:
1) moved "sonar/desktop/src" to "sonar/desktop/app/src", so "app" is now a separate package containing the core Flipper app code
2) Configured yarn workspaces with the root in "sonar/desktop": app, static, pkg, doctor, headless-tests. Plugins are not included for now, I plan to do this later.

Reviewed By: jknoxville

Differential Revision: D20535782

fbshipit-source-id: 600b2301960f37c7d72166e0d04eba462bec9fc1

desktop/app/src/fb-interfaces/Logger.tsx

@@ -0,0 +1,39 @@
+/**
+ * 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
+ */
+
+export type LogTypes = 'error' | 'warn' | 'info' | 'debug';
+export type TrackType =
+  | 'duration'
+  | 'usage'
+  | 'performance'
+  | 'success-rate'
+  | 'operation-cancelled';
+
+export type Args = {
+  isHeadless?: boolean;
+  isTest?: boolean;
+};
+
+export interface Logger {
+  track(type: TrackType, event: string, data?: any, plugin?: string): void;
+
+  trackTimeSince(
+    mark: string,
+    eventName?: string | null | undefined,
+    data?: any,
+  ): void;
+
+  info(data: any, category: string): void;
+
+  warn(data: any, category: string): void;
+
+  error(data: any, category: string): void;
+
+  debug(data: any, category: string): void;
+}