Add additional text clarifying how to match vct and doctype

[GarethCOliver]

Resolves #741 by adding more explicit instructions on what allows a Credential to satisfy vct_values, and applies similar explicit text to doctype_value

This makes use of the SD-JWT VC draft 15 which added aka_vcts for this purpose

[c2bo]

I guess this should also go into 1.0 errata?

#741 also asks about the RP/Verifier side -> Should we add a sentence that these checks must be verified by the Verifier?

Text looks good otherwise imho

[Sakurann]

WG discussion: makes sense to have this in errata, too and also not to limit validation rules to the wallet but also verifier.

[brentzundel]

WG discussion suggests: Make sure it is clear this is an optional feature. @c2bo will propose text.

[GarethCOliver]

From conversation at IETF: SD-JWT-VC intends to add a claim to make it explicit what the super-types of a particular credential are (which will make this trivial and correct).

Until that is in place we shouldn't update this text, and should update to reference it when it is ready. Note that the part of this PR related to mdoc can still go through.

[GarethCOliver]

Updated text to reference the aka_vcts claim, making this nice and explicit.

[fkj]

Did you mean?

Suggested change

	1. The `aka_vcts` claim is present and has at least one element that is contained in the `aka_vcts` array.
	1. The `aka_vcts` claim is present and has at least one element that is contained in the `vct_values` array.

[jogu]

I think if we make this change we have to make it in 1.0 as well - otherwise it's a breaking change in 1.1 and/or 1.0 and 1.1 differ in core behaviour.

But we need to come to a conclusion on #726 first really. If 1.0 is going to reference the latest SD-JWT spec then really 1.0 is going to gain this behaviour regardless, and if we agree on that then making it explicit in 1.0 is best.

(The actual changes in this PR do seem like a sensible way of addressing the problem.)