Expand SemanticallyValid trait

[95DDB]

Would be nice to have, for this trait:

• Derive macros, calling is_valid() on each of the members of a given struct;
• An additional function that allows checking for semantic validity of self given also external data that might be necessary to perform checks otherwise not doable (e.g. if we'd had the circuit associated to a given Marlin pk/vk we would be able to check too that indeed they are the pk/vk associated to that circuit)