Function lookup_key_contact_by_address

async fn lookup_key_contact_by_address(
    context: &Context,
    addr: &str,
    chat_id: Option<ChatId>,
) -> Result<Option<ContactId>>

Looks up a key-contact by email address.

If provided, chat_id must be an encrypted chat ID that has key-contacts inside. Otherwise the function searches in all contacts, preferring accepted and most recently seen ones.