Add add to saved group and combine save groups

[Shane]

I have save d groups for specific tasks and projects I'd like to be able to save new tabs to a previously saved group and to be able to combine two previous saves without reloading all tabs, re-saving, then deleting the previous saved groups.

bonus if I can just Type the name and be prompted
"You already have this group saved, do you want to add these tabs to the existing group?"