Validate: insert phone number errors in table
Validate phone: only print log message when needed
Validate: update familles table with valid phones
Use constants for Mailchimp map

Facilitates maintenance when data fields are added in Mailchimp as the
groupings and system fields are renumbered.

Also added check to ensure that manually added fields (for breakdown of
inscriptions grouping into individual flags) do not overlap with
Mailchimp system fields.