Add support for the FireCracker engine

[schaefi]

Description

FireCracker is a project which aims for running KVM based virtual machines in a fast way. We would like to add support for a firecracker-pilot to allow registration and running of applications inside of FireCracker based virtual machines

Acceptance Criteria

• Implementation of firecracker-pilot exists and is able to startup a FireCracker compatible image, runs an application inside e.g by init="/the/app", redirects input/output channels to the caller e.g via serial console and gracefully handles the shutdown of the VM such that calling the app feels like a native application the system
• Implementation of app registration exists as part of flake-ctl

[schaefi]

As we already made some progress the path for the next steps became clear and this issue was split into the following more task oriented issues:

• 86

• 84

• 83