Tab Groups Support

[hx41455]

First of all thank you for your hard work!

Lepton kinda breaks tab groups. I'm using developer edition Firefox, 136.0b5, with v8.6.6 Lepton (all are as recent as can be as of writing this)

First the expected behavior, an example without Lepton installed. Here's a tab group, noted by the pink line underneath the tabs

And here the tab group is closed all the tabs belonging to the group are hidden

Now with Lepton installed, the pink line under the tabs is gone

And when the tab group is closed in this case the tabs are not hidden but are instead kind of squished

Maybe there are options in user.js I'm unaware of, I couldn't find any mention of tab groups in the wiki; it is after all a very new and experimental feature, disabled by default in about:config