fabric-samples needs a sample external builder implementation

- this should support both building/launching chaincode as well as supporting external chaincode
- ideally written in Go so that it is platform agnostic (so can support nano-bash and a windows native equivalent)
- support TLS and non-TLS
- support all chaincode languages: go, node, java
- Go supports CORE_TLS_CLIENT_CERT_FILE and CORE_TLS_CLIENT_KEY_FILE for standard pem files where as node and java supports CORE_TLS_CLIENT_KEY_PATH and CORE_TLS_CLIENT_CERT_PATH which are base64 encoded pem files

- we should then apply this to the test-network and test-network-nano-bash implementations as we want to move away from an implicit docker dependency (docker-compose and docker to run a local network is still useful but now we could also chose to use things like podman instead)