Create legal mentions

Legal regulation requires various legal mentions:

• Create EULA
  • for IGN instance #144 (closed)
  • for OSM instance #145 (closed)
  • generic/template for upcoming instances #146 (closed)
  • help Map Complete instance writing one https://github.com/pietervdvn/MapComplete/issues/2268
• Create the ToS / legal mentions
  • for IGN instance https://panoramax.ign.fr/terms-of-service
    • fix the broken translations for other languages than FR/EN
  • for OSM instance #147 (closed)
  • generic/template for upcoming instances #148 (closed)
  • help Map Complete instance writing one https://github.com/pietervdvn/MapComplete/issues/2268
  • Make all ToS accepted by users #151 (closed)
• Create the privacy policies
  • for IGN instance #140 (closed)
  • for panoramax.fr https://panoramax.fr/mentions-legales updated both in French and English panoramax.fr-website#10 (closed)
• Create a ToSdr page https://tosdr.org/en/new_service
• Add URLs for all these pages in the footer

Also: let's create a back-office to let the instance manager easily manage these legal mentions