Summary:
This allow websocket client to receive and reply messages from desktop client.
## Changelog
Implement requestResponse for websocket connection, allowing websocket client to receive and reply messages from desktop client
Pull Request resolved: https://github.com/facebook/flipper/pull/1510
Test Plan:
Tested with custom websocket client, allow communicating getPlugins, init, deinit, etc.
But I think it's better to have dedicated unit tests for this (currently there's none?), let me know what you think.
Reviewed By: passy
Differential Revision: D23499396
Pulled By: jknoxville
fbshipit-source-id: fb445c0634afd46a525fc52da33b487da4e591fe
1b80877f1a