Path Migration #5
Description
Socket should be able to support proper path migration. When a better path is detected by the NWConnection, the socket should be able to successfully migrate to a new connection seamlessly.
During this process, the biggest challenge is successfully either finishing or transferring all active continuations. Since a new NWConnection object is built, the instance must be replaced meaning tasks like receive will suddenly point to the new connection instance. Failing to transfer these continuations (or failure in waiting for them to complete) before replacing the connection results in missed messages and leaked continuations.
Options should also be provided for path migration settings.