Credit to Virgile Prevosto

Based on distributives laws

Credit to Virgile Prevosto

Credit to Basile Desloges

Removing all calls to `Bottom` functions on lists without changing the
semantic.

Valentin Perrelle authored 3 months ago and David Bühler committed 2 months ago

- the useful modules definitions are moved to Engine_sig
- the engine contains the modules circularly dependent on the
  engine
- every module circularly dependent on the engine receive the Engine
  as a functor parameter
- Analysis instanciate the Engine recursively

    and its serializer are defined as such.