FAB-10995 runtime_launcher chaincode spec removal

This CR completes the removal of the chaincode spec from the
runtime_launcher.go file.  There is some additional refactoring,
especially of the test required, but this will follow in a subsequent
CR.

Change-Id: I8b71811f534fee6fcda77bc7bafb64c319a10ab3
Signed-off-by: Jason Yellick <jyellick@us.ibm.com>