It's used in a number of source files; don't force each of them to test
GCRYPT_VERSION_NUMBER independently.

Make sure every file that uses HAVE_LIBGCRYPT_AEAD includes
wsutil/wsgcrypt.h.

Also do some other definitions that are based on the libgcrypt version
there as well.

This requires that the Qt UI code be given the include directory for
libgcrypt, as the follow stream code includes
epan/dissectors/packet-quic.h, which includes wsutil/wsgcrypt.h to get
HAVE_LIBGCRYPT_AEAD defined, and wsutil/wsgcrypt.h includes <gcrypt.h>.

Change-Id: I9cb50f411f5b2b6b9e28a38bfd901f4a66d9cc8f
Reviewed-on: https://code.wireshark.org/review/38116


Petri-Dish: Guy Harris <gharris@sonic.net>
Tested-by: Petri Dish Buildbot
Reviewed-by: Guy Harris <gharris@sonic.net>