Qt: rename SummaryDialog class to CaptureFilePropertiesDialog

Change-Id: I79aa63621853ff15b8c568e1c7949fb8fa0caca2
Reviewed-on: https://code.wireshark.org/review/5929
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>
Reviewed-by: Gerald Combs <gerald@wireshark.org>