Expose intern graphQL reuqests to plugins

Summary: Some intern plugins use it, an dit is currently missing in FlipperLib

Reviewed By: timur-valiev

Differential Revision: D36313032

fbshipit-source-id: 5ea8e250f1d0bc8831727abd883d953286a022d4

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

@@ -430,6 +430,10 @@ export function createMockFlipperLib(options?: StartPluginOptions): FlipperLib {
         platform: 'linux',
       },
     },
+    intern: {
+      graphGet: createStubFunction(),
+      graphPost: createStubFunction(),
+    },
     remoteServerContext: {
       childProcess: {
         exec: createStubFunction(),