Introduce proper term for payload (before turning it into a JWT)

[danielfett]

There is currently no good name for the claims before they are packaged into the SD-JWT. "Payload" can refer to the payload of the SD-JWT, which may not contain all user claims.

[bc-pi]

I'm not sure what the term should be but I'd agree that text like what we've got now, "object as the set of claims that the Issuer is issuing" from sec 5 isn't easy to say or particularly meaningful out of context :)

[Sakurann]

We use "the set of claims that the Issuer is issuing" when explaining in the Examples section what is in the payload. I kind of like it?

[bc-pi]

"input claim set" seems to be directionality correct

[Sakurann]

PR merged