doxygen: fix errors + code cleanup

src/contrib/dnstap/reader.h

src/contrib/qp-trie/trie.h

src/contrib/sockaddr.h

src/contrib/time.h

src/contrib/ucw/binsearch.h

src/contrib/ucw/lists.c

src/contrib/ucw/lists.h

src/contrib/ucw/mempool.c

src/contrib/ucw/mempool.h

src/dnssec/lib/dnssec/key.h

src/dnssec/lib/list/ucw_clists.h

src/dnssec/lib/nsec/hash.c

src/dnssec/lib/sign/der.c

src/dnssec/shared/pem.c

src/dnssec/shared/pem.h

src/knot/common/evsched.h

src/knot/common/fdset.h

src/knot/common/log.h

src/knot/common/process.h

src/knot/common/ref.h