Add support for intellisense in remote module imports/reference

[nonsocode]

When working with modules, it would provide a better developer experience to be able to list out template specs and versions with intellisense.

{
  "moduleAliases": {
    "ts": {
      "alias": {
        "subscription": "0000000-000-0000-0000-000000000000",
        "resourceGroup": "my-resource-group"
      }
    }
  }
}

When trying to reference a particular version in my module, I get no intellisence to get the actual versions available

module myModule 'ts/alias:my-template-spec:'

                                           ^ No intellisense to list versions available

The same applies to listing template specs in the resource group

module myModule 'ts/alias:'
                          ^ No intellisense to list template specs in the resourcegroup