PoC: running experiments bypassing internal/engine

[bassosimone]

This PoC investigates whether it would be possible to run experiments directly without using the internal/engine abstraction as the middle man.

The PoC is in the context of https://github.com/ooni/ooni.org/issues/1295

Checklist

• [ ] I have read the contribution guidelines
• [ ] reference issue for this pull request:
• [ ] if you changed anything related to how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request:
• [ ] if you changed code inside an experiment, make sure you bump its version number

Description

Please, insert here a more detailed description.