Artem Grinev authored Mar 16, 2022 and Nate Graham committed Mar 16, 2022

This implements Blue Ocean style for scrollbars. Also makes them look focused
on main content view focus.

Opacity levels were found based on QStyle element final colors as it seems
GTK handles alpha a bit differently.

BUG: 443919
BUG: 446824
FIXED-IN: 5.25