DNS: replace hash map by red-black tree to fix request/response tracking when transaction id is reused

Bug: 10657
Change-Id: Id4356dcd6802da40b4a3e2e2095cc9d2932c2c68
Reviewed-on: https://code.wireshark.org/review/5100
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Evan Huus <eapache@gmail.com>