Create tool to migrate existing cds/tgz chaincode packages

[jt-nti]

It might help people migrate to the k8s builder if there was a tool to create a template project and seed it with the contents of an existing chaincode package.

Traditional Go, Java, and Node chaincode packages contain the smart contract source code which is compiled by a chaincode builder container. (Note: Java packages may only contain prebuilt jars in some cases.)

Packages for the new lifecycle are just tarballs, and packages for the old lifecycle are protobuf based- see cds-cli for an example of how to read those.

A new repo would be required for the new tool but opening this issue here for discussion.