Bug 1082627 - Align collapsed group items to the left. r=kgrandon
Bug 1082627 - Add marionette test to verify collapsing group UX. r=kgrandon

Add a marionette test that verifies that collapsing a group shrinks icons
and that they're left-aligned.
Merge pull request #25140 from Cwiiis/bug1082627-collapsed-groups-align-left

Bug 1082627 - Align collapsed group items to the left. r=kgrandon