[FEATURE] Add Terraform support for azurerm_user_assigned_identity

[BernieWhite]

Your suggestion

Using azurerm_user_assigned_identity along side azapi resources is common in Microsoft Learn docs used along side azurerm_resource_group.

Let's add support for this resource type because it has a relatively low number of properties that can be configured.

Alternatives

n/a

Additional context

• https://learn.microsoft.com/en-us/azure/developer/terraform/get-started-azapi-resource?tabs=azure-cli