Fix for #1132

Fixes #1132 (closed) and improves human readable output for certs with user principal name SANs and "smart card logon" key purposes. Adds new tests to confirm that the fix is functional, i.e. that UPN name constraints can be parsed and that a leaf node with a DNSname constraint does not fail validation when issued from a CA with UPN name constraints.

Checklist

• Commits have Signed-off-by: with name/author being identical to the commit author
• Code modified for feature
• Test suite updated with functionality tests
• Test suite updated with negative tests
• Documentation updated / NEWS entry present (for non-trivial changes)
• CI timeout is 2h or higher (see Settings/CICD/General pipelines/Timeout)

Reviewer's checklist:

• Any issues marked for closing are addressed
• There is a test suite reasonably covering new functionality or modifications
• Function naming, parameters, return values, types, etc., are consistent and according to CONTRIBUTION.md
• This feature/change has adequate documentation added
• No obvious mistakes in the code