IIUC the API needed for this addon[1] will be available in FF 59[2].
Mozilla dropped support for Tab Center a while before Quantum IIRC. Another addon took its place, but then was dropped by its developer with Quantum. Supposedly [1] will allow transition from the older addons. I'm looking forward to finding out once 59 is out.
[1]https://addons.mozilla.org/en-US/firefox/addon/tab-groups/ [2]https://bugzilla.mozilla.org/show_bug.cgi?id=1423725