Dissect an SVHDX Open Device Context that appears as an Extra Create Parameter
in a CREATE request. This helps understand HyperV over SMB 3.x stuff.

Bug: 10527
Change-Id: I1e206ed38e12fed419b1ac4a0793b91f9308f364
Signed-off-by: Richard Sharpe <rsharpe@samba.org>
Reviewed-on: https://code.wireshark.org/review/4477
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Reviewed-by: Evan Huus <eapache@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>