add an exhaustivity parameter to Branch constructor in Machine Code to handle C switch default case optimization in case of a singleton enum

remove reset_cleared strategy from the FramaC plugin, and add optimization level parameter to test file

give up on reusability, artifacting _opam and _build exceeds maximal size of artifact, we're just going to rebuild everything for now

use artifacts instead of caching since caching does not seem to work with shared runner and the runner on prise suffer for connection pbs