Describes the authentication method of the organization. Ad hoc authentication
means that users are exclusively added via explicit group membership And must
use a 'sign-in via' option. Domain authentication means that users may login
via their email address, must in the case of custom identity providers, that
maps from domain to an identity provider.
Describes how to lookup the provider, when "global", use a built in generic provider
e.g. Google/Microsoft, when "organization", use an organization scoped provider.
The ID of the provider to use, the scope is determined by useCustomProvider.
If false, this refers to a built in provider, if true, then to an organization
specific one.