Convert socks-rtc to use new core.tcpsocket API

* Convert socks-rtc to use new core.tcpsocket API
* Remove unused methods from tcp.ts
* Change freedom library from "freedom-runtime-chrome" to "freedom-for-chrome"
* Tested with echo-server and performed end-to-end test using "curl -x socks5h://localhost:9999 www.google.com"
* Will create a separate pull request to update typescript API at node_modules/freedom-typescript-api/interfaces/tcp-socket.d.ts