The dst_key_pubcompare() and dst_key_compare() didn't have a unit test, add the unit tests which test comparing the same keys, different keys, and, where possible, similar keys with a manually altered parameter. dst_key_pubcompare() internally uses the *_todns() functions of the lib/dns/openssl*_link.c modules. dst_key_compare() internally uses the *_compare() functions of the lib/dns/openssl*_link.c modules.