feat(build): Invoke pkgctl offload server subcommand over ssh
Use a client-server script invocation instead of piping complex shell commands as pure strings to the remote. Now we call a server use only component on the remote server to execute the desired build.
This change allows for properly developing the remote command without golfing around shell strings and while having appropriate completion, syntax highlight and LSP support. As a side-effect we are now not depending on a POSIX compliant login shell anymore, as we simply invoke a pkgctl subcommand schema.
Supersedes !293
Edited by Levente Polyak