New "Isolate Active Group" Isolation Mode.
Users now have two layer isolation mode options.
The original "Isolate Active Layer" (context menu item or alt+click) mode that displays only the active
layer, as well as a new "Isolate Active Group" (context menu item only
for now) mode that displays all of the sibling layers in a given group.
Requested by Bollebib!
BUG:377468