more tlsa fixes

git-svn-id: https://gnunet.org/svn/gnunet@33576 140774ce-b5e7-0310-ab8b-a85725594a96
draft hex2bin, bin2hex

git-svn-id: https://gnunet.org/svn/gnunet@33577 140774ce-b5e7-0310-ab8b-a85725594a96