Add advanced matching/identification support to FacebookPixel adapter

See facebook's docs for details, but essentially it looks like the user identifying information needs to be passed in the `init` method:

https://developers.facebook.com/docs/facebook-pixel/pixel-with-ads/conversion-tracking#advanced_match

Start with the FacebookPixel adapter and its init method, then read Facebook's advanced matching documentation linked in the issue. Identify how user identifying information should be supplied during initialization; done means the adapter passes that information as required by the documented integration.

Rédigé par le modèle d'indexation à partir du texte de l'issue.