CacheSupportedProviders attempts to retrieve the supported Resource Providers from the Resource Manager API and caches them, for used in enhanced validation.

DetermineResourceProvidersRequiringRegistration determines which Resource Providers require registration to be able to be used.

EnhancedValidate returns a validation function which attempts to validate the Resource Provider against the list of Resource Provider supported by this Azure Environment.

RegisterForSubscription registers the specified Resource Providers in the current Subscription.

RequiredResourceProviders returns all of the Resource Providers used by the AzureStack Provider whilst all may not be used by every user - the intention is that we determine which should be registered such that we can avoid obscure errors where Resource Providers aren't registered.