Add contact type to contacts and allow setting it in admin
Treat FOI contacts differently for org home page lists

Much like the main office for world orgs on their home page list of offices we allow FOI contacts to be added to the org contacts list, but we filter them out of the list of contacts.  We also don't present the yes / no choice on the form, or add/remove buttons on the list if it is an FOI contact.
Use home page list of contacts on exec office frontend page
Fetch the list of foi_contacts from an org and show on the home page
Pull the FOI links out of the sidebar and into the FOI contact section

Only if the org *has* foi contacts, otherwise leave them where they are.
Test that we can't put foi contacts on the home page via admin
Show the office type on the world office admin

It's a bit confusing with office type + contact type, maybe we just hide contact type for world offices (default it to general)?
Show home_page_contacts on exec office pages rather than all

So they respect the defined order.  This does mean any FOI contacts will suddenly disappear as we don't pull them out separately yet, but there shouldn't be any for exec offices though, so this will be ok for now.