Maybe: Relax 'label' requirement for deferred named fragments

[calvincestari]

The label is required for naming purposes on deferred inline fragments however for named fragments we already have been given something to name it. It's still unknown whether the label will be required for execution.

The work here is to relax the requirement for a 'label' argument on deferred named fragments only, and only once execution of deferred fragments has been implemented so we're sure it's absolutely not needed.