Preparatory work regarding site charter acceptance

• Add a bollean field to the user model (defaults to false) to tell if the user has accepted the sites charter and data processing rules,
• Create a Django view that holds a dumb charter and rule. If the user hasn't accepted them, add a button to accept the rules.
• Update the loginRequieredMidlleware to redirect all request to that view until the user accept the rules.
• The view must be accessible even if the user has already accepted the rules.