Design the interfaces for the autopkgtest and lintian tasks

The "interfaces" of Autopkgtest and Lintian tasks consist of:

• the JSON configuration data that can be submitted to those tasks
• the artifacts consumed and produced
• the relationships created

We want to define those interfaces so that they cover the various features of autopkgtest and lintian. Not all features need to be made available but the set should be large enough to enable most reasonable experiments.

For autopkgtest in particular, we believe that the possibility to let autopkgtest build the binary packages out of the source package should not be supported since, in the context of debusine, we really want to let debusine in charge of building the packages.

For lintian, we want to explore how we can run different versions of lintian (from different Debian releases in particular).

The resulting "interfaces" should be documented in Debusine's official documentation.

• Come up with a draft of those interfaces
• Get the draft reviewed by autopkgtest, ci.debian.net and lintian maintainers to validate our design
• Integrate their feedback and drop the draft status