Refactor code to remove letter branding from an org
Refactor code to remove letter branding from an org

Since the `.organisation_letter_branding` endpoint will become more complex,
this copies the approach taken for email branding and splits out the
code to remove letter branding for an organisation into a private
function.

alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin