Is there any code in the Raiden client that deploys a TokenNetworkRegistry contract?
The client, generally, will not deploy a new token network registry. Through the REST and Python APIs it may register a new token with an existing registry, but the deployment of the registry is done without the client.
With that said, it is possible for a user to run Raiden with the console interface and the use the existing code to deploy any smart contract. There is code to deploy smart contracts in the JSONRPCClient class.