Provider 3.0 changes

[waylew-lexis]

upcoming major release of azurerm provider changes may introduce breaking changes hashicorp/terraform-provider-azurerm#14193

Storage:

• We’ll switch to using Resource Manager (management plane) for all resources.
• Switching to use AzureAD / Resource Manager for nested item configuration - this allows provisioning these when Private Link is enabled, however requires different permissions which are not granted by default.
• The field allow_blob_public_access will be renamed to allow_nested_items_to_be_public to resolve confusion about what this field does. This field specifies whether items within the Storage Account (such as Containers and Blobs) can opt-in to being made public (for example at the Container or Blob level) - and not that all resources within this Storage Account are public by default.