Add minimize and maximize buttons to the SCTP analysis windows.

As suggested by Jeff Morriss.

Change-Id: Ibe2d30c31d51ab92377d64068527b424a92e8a64
Reviewed-on: https://code.wireshark.org/review/5361
Petri-Dish: Jeff Morriss <jeff.morriss.ws@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Jeff Morriss <jeff.morriss.ws@gmail.com>
Tested-by: Jeff Morriss <jeff.morriss.ws@gmail.com>
Reviewed-by: Evan Huus <eapache@gmail.com>