Checklists V2

[erjosito]

This is a PR to bring the checklists framework to a new version. Some of the highlights of the new format:

• Recommendations are stored in individual YAML files.
• Checklists are collections of recommendations, that can be created with recommendation "selectors".
• v1 checklists can still be generated for compatibility with the existing tooling.

Before the migration there is some work that needs to be done:

• Migration scripts created, to make sure that we don't lose any data.
• Tooling around analysis of the recommendation body.
• Schemas for both the reco and the checklist files defined.
• Github action to verify the schema (as well as other aspects such as the uniqueness of reco names) in a PR.
• Github action to tag PRs depending on which checklist is impacted by reco updates, specially for ALZ.
• Automatic generation of v1 checklists at push time - WIP
• Update documentation