minor: basic models implementation with links
Models + Migration based on this diagram (snake_cased):
I tried to implement choices lists based on the big sheety-sheet. I may have miss some of them. I don't know how to validate this.
Not Implemented:
- ProductionStatistics - As stated, we will wait for more information about who will consume those datas. Depending on the answer, doing it client-side may be the proper way.
Merging to update/new_permissions