* feat(demarche): description
Show the description of an opendata procedure (published or draft),
with help about how to prefill a dossier for this procedure.
Co-authored-by: Damien Le Thiec <damien.lethiec@gmail.com>
* store prefill params in session
Instead of using query params on /dossier/new, we assume the user comes
from /commencer/:path, which is the new prefill link.
There, we store the prefill params in session, and use them to prefill
the dossier when creating it, in /dossiers/new.
* spec: cover the case
* review: serialize with json instead of yaml
* review: rename method
* review: store only query params
* review: comment why we dont override already stored params
