Research how to handle custom domains and site deletions.

[apburnes]

When a user deletes a site with custom domain/s associated to it, add functionality to delete the external domain service related to the custom domain/s

Acceptance Criteria

• [ ] Research the workflow for deleting a site
• [ ] Do we add notices during the site delete process that the custom domains will be deleted?
• [ ] Do we make de-provisioning the custom domain required before a site can be deleted?

[davemcorwin]

We created https://github.com/18F/federalist/issues/3879 to prevent site deletion if there is a custom domain. I think this is OK for now and probably later when we push out custom domain management to users. I don't think it is a bad thing to force a user to explicitly remove the domain before removing the site. If y'all agree, can we close this issue?

[apburnes]

Closing for different workflow.