[!351] Option validation via cerberus

Merge branch 'feature/option-validation-new' into 'master'

ref:extensions/dune-codegen Note: Created a new updated branch to not loose
anything in the old one. I still need to see if everything is working.

See merge request [extensions/dune-codegen!351]

  [extensions/dune-codegen!351]: gitlab.dune-project.org/extensions/dune-codegen/merge_requests/351