Remove 'path' from plugins

Summary:
1. Add `path` replacement
1. Remove Node's path for all plugins but MobileBuildsPluginContainer (it is probably going to be moved to the server)

Reviewed By: mweststrate

Differential Revision: D32766327

fbshipit-source-id: e636f273842506e752b97cf1b28ce7ac51ce9a12

desktop/flipper-plugin/src/index.ts

@@ -129,6 +129,8 @@ export {
 export {createTablePlugin} from './utils/createTablePlugin';
 
 export {textContent} from './utils/textContent';
+import * as path from './utils/path';
+export {path};
 
 // It's not ideal that this exists in flipper-plugin sources directly,
 // but is the least pain for plugin authors.