Closes #44

fix: irmaclient now updates its credential instances if new attributes were added by the scheme manager

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.

When disclosing two attributes from the same credential instance, irmaclient would disclose both attributes twice.

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

Further refinements to CredentialInfo to make it consistent with description structs for irma_configuration

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

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

- Extract raw information from session, and only derive for display
- Add protocol version and ABS timestamps in log entries. Include an update function for existing logs
- AttributeValue of AttributeResult is now a TranslatedString
- Removed polymorphic 'response' from log entry; populate either IssueCommitment or Prooflist instead
- Greatly simplified marshalling log entries by not using a separate struct
- Added tests for disclosure logging

Co-authored-by: Sietse Ringers <mail@sietseringers.net>

Before 42a3acc2, more than one instance of the singleton credential type may have been stored.