add intent to retain to claims query in DCQL

[Sakurann]

resolves #321

[paulbastian]

I'm not in favor of adding this and I think there have been good reasons/argumentations in the Issue. In short, the feature as-is is under-specified and likely of not much use and it seems more reasonable to convey this via the purpose field.

[Sakurann]

WG discussion: agreement that this is not perfect (PR text should be improved), but probably good enough as a starting point to meet the requirements and have a transition path for those who us intent_to_retain in 18013-5/PE.

[nemqe]

A potential issue I see is that if this option is added in this form it will probably need to be maintained in the version it is introduced as it could be a breaking change to remove it. (maybe a parallel mechanism can be introduced that could be marked as preferred in 1.1? something like PEX vs DCQL)

Other than that if the group is short on time and this option is required it may be a good compromise until a better mechanism is found.

[Sakurann]

if this option is added in this form it will probably need to be maintained in the version it is introduced as it could be a breaking change to remove it

the feature is optional. I don't think we plan to remove it, but if we come up with a better mechanism in v1.1 in the future, we can recommend that feature over intent_to_retain.

another option I considered when doing PR is to add intent_to_retain only to mdocs, but that did not feel in sprit of the specification, or the discussions we have been having..

[peppelinux]

good one!

[c2bo]

I am still not fully convinced that this feature on its own makes sense, but as it is an optional credential format specific feature that just matches the current capabilities in the ISO protocols, I guess it is fine to merge.

We can (and probably should imho) provide another solution in the direction of purpose in the long run.

[awoie]

IMO, this would cause interop issues. I know that certain members are in favor of providing some guidance to the user but it would cause confusion if this was done only for mdocs.

verbal approval to dismiss during the wg call