In particular, combined issuance sessions in which 2 or more attributes are
requested from one particular credential type, due to a miscalculation during
verification of the attributes.

Fixes #36

feat: Breaking change: support conjunctions of disjunctions of conjunctions when requesting attributes in any of the three supported session types

Instead of requesting several attributes, one can now request several groups of attributes. Within each such group, attributes belonging to the same credential type always come from the same credential instance. This affects all three session types, as in each of them attributes can be disclosed.

Co-authored-by: Confiks <confiks@scriptbase.org>

Co-authored-by: Confiks <confiks@scriptbase.org>

Co-authored-by: David Venhoek <david@venhoek.nl>

Co-authored-by: Confiks <confiks@scriptbase.org>

Co-authored-by: Confiks <confiks@scriptbase.org>