Expose env via flipperLib

Summary:
This change exposes the env variables via the FlipperLib interface used by plugins.

The variables are already white-listed and safe to be used by plugins according to documentation.

Reviewed By: antonk52

Differential Revision: D40852147

fbshipit-source-id: bbb3b052d33bf5cf75c81166af2400fe6a359256

desktop/flipper-plugin-core/src/plugin/FlipperLib.tsx

@@ -26,6 +26,7 @@ import {
   EnvironmentInfo,
   FSStatsLike,
   FlipperServerCommands,
+  ENVIRONMENT_VARIABLES,
 } from 'flipper-common';
 import {CreatePasteArgs, CreatePasteResult} from './Paste';
 
@@ -199,6 +200,7 @@ export interface FlipperLib {
   };
   environmentInfo: {
     os: EnvironmentInfo['os'];
+    env: Partial<Record<ENVIRONMENT_VARIABLES, string>>;
   };
   remoteServerContext: RemoteServerContext;
   intern: InternAPI;

desktop/flipper-plugin-core/src/test-utils/test-utils.tsx

@@ -74,6 +74,7 @@ export function createMockFlipperLib(options?: StartPluginOptions): FlipperLib {
         unixname: 'test',
         platform: 'linux',
       },
+      env: {},
     },
     intern: {
       graphGet: createStubFunction(),