Add ability to disable inactive tabs in mobile browser.

[PonyFlare]

Is your feature request related to a problem? Please describe. Tabs annoyingly being marked as inactive in WF Android.

Describe the solution you'd like Add option that has been in mozilla-mobile for 3 years to disable marking tabs inactive.

Describe alternatives you've considered .... Use a brower that has this feature, I suppose.

Additional context https://github.com/mozilla-mobile/fenix/issues/20684 Screenshot from FF Showing option that is not in WF.

[mgoldsworth]

I really want this implemented. The inactive tabs section is distracting and jarring to me.

This is the only thing making my switch from Firefox painful, and is enough that I'm looking at alternatives. I really like WaterFox, but I need to never see inactive tabs negatively impacting my experience.