Enable mousewheel scrolling on tab bars (without switching)
A behavior I miss from Firefox when using GNOME Web is being able to scroll through an overflowed tab bar and have the tab bar scroll without switching between tabs.
Steps to reproduce
- Use mouse wheel over tab bar to scroll up or down
Like Firefox prior to version 65; Tab strip should scroll, but tabs should not be switched to. Users can click on a tab as usual to switch to it.