Cleanup running containers on the Control-C signal

[ammernico]

• Add the signal feature to tokio to interrupt and handle the Control-C signal in Butido.
• Add Control-C signal handling into the Orchestrator.
• Implement Drop on the JobHandle to ensure container cleanup.

This is a working draft pr for testing purposes and still missing some features.

[christophprokop]

Tested while multiple containers were running on all build hosts. All containeres were successfully stopped after just a few seconds. Nice! :)