Lazy-Mode: Set copyDirs to copy_whole_modpack to copy complete modpack to server pack

For the lazy folks who can not be bothered to check which directories and files they need, offer lazy mode. Said lazy mode bears risks, so users must be warned about potential issues, server pack and server pack archive sizes.

Only if copyDirs.size() == 1 and copyDirs.get(0).equals("copy_whole_modpack")