Analyst/superuser can cancel a domain invitation in django admin

[abroddrick]

Issue description

Analysts and superusers can cancel an invitation in the Domain Mangers page of a domain, so it makes sense they should be able to cancel an invite on django admin. However, right now we don't allow anyone to change the state on django admin for invitations, making it impossible for any one to change an invited domain invitation to "canceled".

Acceptance criteria

• domain invitations can be canceled in django admin
• domain invitations still cannot be manually marked as retrieved or invited (this would cause issues in other code areas)

Additional context

No response

Links to other issues

• relates to Content: Create email to send when a domain invitation has been canceled #2887
• relates to Allow analysts to view cancelled invitations  #1604