* Parquet: Change "tcp_hs_rt" field to type double with precision to 3 decimal places * C-DNS: Improve values stored to "round_trip_time" to actual microsecond precision. Item format stays the same, only the last 3 digits aren't always zeros anymore. * dnstap: Parse RTT estimate from "extra" byte field as exported by Knot Resolver >= 5.3.2 * Logger: Append to existing log file instead of rewriting it * Bugfix: Add missing "qr-signature-index" hint in storage hints of C-DNS file preamble