Create a docker image that can deploy various testnets on the same server

During YPP testing and Ephesus runtime testing, the community was faced with a difficulty arising from deploying more than one testnet on the same server. Of course, it could be done manually by configuring ports, but required certain DevOps experience and also this was prone to errors and time-consuming.
A solution was proposed : a docker image that can be used to setup various chains on the same server without resulting in port errors.