add an option to "restore and delete" a tab group

[DelusionalOptimist]

Current Behavior
There is no option to restore and also delete the tab group.

Desired Behavior
Give an option to users so that they just have to single click in order to restore the group and also delete it immediately. This can co-exist with the current "restore but keep group" feature.

Reasons to have this in
People may use TabuRei for saving tabs temporarily (not for future reference). The current approach works but people might be lazy to clean stuff up. Having this in makes their lives easier :P