RG mode: uses azlist with rg included, with special handling for empty rg

[magodo]

This PR is an improvement on #500, that we leverages the azlist to include the resource group being listed as part of the resource list. The benefit of this is that azlist will pick up any extension resources for the resource list, including the resoruce group itself (which solves the #573). The only thing need special handling is that for empty resource group, the resource group won't be listed, in which case we'll have to manually add the resource group to the resource list.

Fix #573

[giuliohome]

Thank you very much for the super fast fix! 🚀

However, after a first test from the source repo branch,

giulio@WPWS19069419:/mnt/c/Dati/golang/aztfy$ git branch -vv
* rg_use_azlist f6bad23 [origin/rg_use_azlist] RG mode: uses `azlist` with rg included, with special handling for empty rg

I still can't see the role assignment, what am I missing now?

giulio@WPWS19069419:/mnt/c/Dati/golang/aztfy$ ~/go/bin/aztfexport rg --append --include-role-assignment --output-dir tf_
test -n my-rg
giulio@WPWS19069419:/mnt/c/Dati/golang/aztfy$ cat tf_test/main.aztfexport.tf

resource "azurerm_resource_group" "res-0" {
  location = "westeurope"
  name     = "my-rg"
}

Thanks in advance for your clarification.