Update Solidity according to new NFTattestation

[jot2re]

Update the Solidity code according to the refactoring done when handling issue #203 and #201

[oleggrib]

@jot2re in case if we implement #203 then SmartContract need to change single sinnature verification update. so whole object will be signed with attestor address.

And another suggestion - with new flow we can make simplier object with required fields only to save gas

so we need:

• timestamp
• nftsList
• identifier
• whole_Object_Signature_By_Attesdtation.id_Key

its enough for our task.

universal solution is a good option when data validation is free, but in our case use have to pay gas for our unification

cc @colourful-land , @JamesSmartCell