YC-1136

[AlexandreJunod]

Remake contacts to use the db instead of being an enum.

• Rename ContactType by ContactForm. Type is used to define the ContactType of a contact, ContactForm is used to define which contact is used in witch form_category.
• Adapt method and field names to use form instead of type
• ContactType can be added by admin without changing any code
• User can add new contacts multiple times based on integrator configuration
• API handles multiple times the same type of contact

TODO :

• Adapt reports
• Check if "Auteur" isn't a problem in the contacts list, as it is used only to print correctly in reports and can be avoided
• Check every variable/method/field to be sure the name is appropriate
• Check every migration is working correctly