Az config set allows for misleading error descriptions.

**Resource Provider**
Az config

**Description of Feature or Work Requested**
Is there any way we can tell through the code when an argument (e.g. resource group) was enforced by the default configuration? We want to have a more descriptive error. Right now it says that the resource was not found. But in commands like show, we have a way to find the resource group when it isn't provided and the error saying the resource isn't found is misleading. We would like a more descriptive error that shows when the user has a default rg config we can warn them in case of a resourceGroupNotFound error.