Extract environment config initialisation to server-core

Summary: This diff makes most stuff that is read from the `os` package, and version info etc available from the `serverConfig` object, so that flipper-ui-core no longer needs the `os` package.

Reviewed By: passy

Differential Revision: D32694848

fbshipit-source-id: 93af1e95d898da9aaf351a6970b5a7652ee835c8

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

@@ -8,15 +8,13 @@
  */
 
 import {FlipperServer, FlipperServerConfig} from 'flipper-common';
-import {getRenderHostInstance} from 'flipper-ui-core';
+import {getRenderHostInstance, RenderHost} from 'flipper-ui-core';
 
 export function initializeRenderHost(
   flipperServer: FlipperServer,
   flipperServerConfig: FlipperServerConfig,
 ) {
   window.FlipperRenderHostInstance = {
-    processId: 0,
-    isProduction: window.flipperConfig.debug !== true,
     readTextFromClipboard() {
       // TODO:
       return undefined;
@@ -72,7 +70,7 @@ export function initializeRenderHost(
       // eslint-disable-next-line no-eval
       return eval(source);
     },
-  };
+  } as RenderHost;
 }
 
 function getDefaultPluginsIndex() {