New BOT Action - Block / Unblock Contact for WhatsApp Business API

It would be great to have the "Block Contact" & "Unblock Contact" action for WhatsApp Business API on the Bot.

This could facilitate for exemple the management of Opt-in / Opt-out for customers who use the Bot associated with broadcast campaigns.

The typical use case is where the user asks for an opt-out, by automatically blocking them with an action on the Bot, we ensure that the user will no longer receive messages from that number.