[MS] provider/azurerm: Virtual Machine Scale Sets with managed disk support (#13717)
[MS] provider/azurerm: Virtual Machine Scale Sets with managed disk support (#13717)

* added vmss with managed disk support

* Update vmss docs

* update vmss test

* added vmss managed disk import test

* update vmss tests

* remove unused test resources

* reverting breaking changes on storage_os_disk and storage_image_reference

* updated vmss tests and documentation

* updated vmss flatten osdisk

* updated vmss resource and import test

* update name in vmss osdisk

* update vmss test to include a blank name

* update vmss test to include a blank name

abhijeetgaiha/terraform-provider-azurerm,thiagocaiubi/terraform-provider-azurerm,thiagocaiubi/terraform-provider-azurerm,abhijeetgaiha/terraform-provider-azurerm,sebastus/terraform-provider-azurerm,abhijeetgaiha/terraform-provider-azurerm,sebastus/terraform-provider-azurerm,sebastus/terraform-provider-azurerm,thiagocaiubi/terraform-provider-azurerm