Create flipper-server-client package

Summary:
FlipperServerClient is a useful abstraction for any JS-based client of headless Flipper. No need to bundle it with flipper-frontend-core, as the rest is not useful for external clients.
Currently, I am planning to add it to jest-e2e to send commands to Flipper

Reviewed By: lblasa

Differential Revision: D40765668

fbshipit-source-id: af48710bb15444ac1ecd649fe9a2ab252f3088f3

desktop/flipper-ui-browser/package.json

@@ -16,6 +16,7 @@
     "eventemitter3": "^4.0.7",
     "flipper-common": "0.0.0",
     "flipper-frontend-core": "0.0.0",
+    "flipper-server-client": "0.0.0",
     "flipper-ui-core": "0.0.0",
     "invariant": "^2.2.4",
     "metro-runtime": "^0.70.2",

desktop/flipper-ui-browser/src/index.tsx

@@ -9,7 +9,7 @@
 
 import {getLogger, Logger, setLoggerInstance} from 'flipper-common';
 import {initializeRenderHost} from './initializeRenderHost';
-import {createFlipperServer, FlipperServerState} from 'flipper-frontend-core';
+import {createFlipperServer, FlipperServerState} from 'flipper-server-client';
 
 document.getElementById('root')!.innerText = 'flipper-ui-browser started';
 

desktop/flipper-ui-browser/tsconfig.json

@@ -13,6 +13,9 @@
     {
       "path": "../flipper-frontend-core"
     },
+    {
+      "path": "../flipper-server-client"
+    },
     {
       "path": "../flipper-ui-core"
     }