Refactor/migrate from popper to floating ui

#356

https://github.com/floating-ui/floating-ui#:\~:text=Security-,Note,-Popper%20is%20now

Note

Popper is now Floating UI! For Popper v2, visit its dedicated branch and its documentation. For help on migrating, check out the Migration Guide.

Flèche

J'en ai profité pour refactor la façon dont on gère le positionnement de la flèche (cf la doc https://floating-ui.com/docs/arrow et mon commit de refacto !636 (23f9476d))

To check

• Explain what has changed in the changelog