Fix begin date & add enddate to each step in procedure.json

[boogheta]

No description provided.

[teymour]

done via 30e1cd3 and b4161b9

[boogheta]

mmm, didn't realize before but we have an issue with the beginning date which is set to the same value for each step of the text, the enddate given here is actually the real beginning date in some cases and the end date in others.
We probably need to evaluate more from the page or from the interventions. recoding of the parse_dossier_senat seems more and more like the way to go :/

[teymour]

Partialy true. The begining and end date are good for the senat. For the AN, the seant's dossier page doesn't contain the information => as the begining date is false, the script removes it : 62bea04