feat(azure): Allow specifying the resource group

[jaitaiwan]

Typically, when deploying resources in Azure, the user is expected to provide a name of a resource group that is either in existence or will be created by the command.

E.g. for AKS:

az aks create \
  --resource-group $MY_RESOURCE_GROUP_NAME \
  --name $MY_AKS_CLUSTER_NAME \
  --node-count 1 \
  --generate-ssh-keys \

Or for Azure RedHat Openshift:

az aro create \
  --resource-group $RESOURCEGROUP \
  --name $CLUSTER \
  --vnet $VIRTUALNETWORK \
  --master-subnet master-subnet \
  --worker-subnet worker-subnet \
  --version <x.y.z>

When using our terraform templates, creating a resource group and attaching the service principal to it (reducing the scope of the role binds as a result) I cannot specify for the azure environment to use it. This changes that by allowing for the resource group to be specified.