Enhancement: AFN: add multiple contact addresses

When I am contacting forges, often I have to add multiple contact addresses since they don't have one single address that is responsible for the forge and I have to scrounge in git repos for addresses. I insert those addresses into the comment field prefixed with "Full contact list:" and copy-paste them into the initial forge contact email, then edit the mail file in my MUA's Outbox Maildir to fix the Reply-To/etc headers.

This workflow is a bit tedious and time consuming, so I would like an enhancement to add multiple forge contacts.

The user experience should work something like the tarball workflow; an "Add contact" button next to the first contact item (probably to the left), and "Remove contact" buttons next to the other contact items.

In addition, a greeting/salutation field for "foo" part of the wording of the "Hello foo" line in the email is needed. When there is one contact it should be populated automatically with the contact's name. When there are multiple contacts all with the same name it should be populated automatically with that name. When there are multiple contacts with different names it could be populated with "git.foo.org folks" or left for the user to fill out.

The additional contact addresses should be passed to the email generation when clicking on the "Send a message to the forge" action.