When rendering a diff for an object value within a resource, Terraform
should always display the value of attributes which may be identifying.
At present, this is a simple rule: render attributes named "id", "name",
or "tags".
Prior to this commit, Terraform would only apply this rule to top-level
resource attributes and those inside nested blocks. Here we extend the
implementation to include object values in other contexts as well.
ad9c89fc19