Qt: disable Capture File Properties toolbar icon by default

Otherwise it can be opened by clikcing on the icon just after launching Wireshark
Also update tooltip to match the exact dialog name

Change-Id: I5ce5e0c24f3dfb44c2303c78114102c5c03ccc88
Reviewed-on: https://code.wireshark.org/review/5930
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Reviewed-by: Gerald Combs <gerald@wireshark.org>