* delete obsolete cncd code
jsonrpc2 client+server, and the utils that used them (piped, pipec)
are not used anymore.
jsonrpc2 was replaced with grpc
piped+pipec were replaced by agents
* delete duplicate section in swagger file
* comment typos
* go mod tidy (websocket+jsonrpc2 no longer used)
* go mod vendor
Co-authored-by: Anbraten <anton@ju60.de>