WIP - Add touristic content and event

- [ ] Touristic content models
  - [x] Extract email and url from contact
  - [ ] Generic lists
- [x] Touristic event models
  - [x] Extract email and url from contact
- [ ] Touristic content fixtures
- [ ] Touristic event fixtures
- [ ] Touristic content edit form and template
- [ ] Touristic event edit form and template
- [ ] Touristic content detail template
- [ ] Touristic event detail template
- [ ] Computed areas
- [ ] Translations
We have this code at a lot of places in the project (intervention, etc...). I guess we can foresee a mixin, maybe when implementing #1219