Comment 6 for bug 1205144

I thought about this a bit more as there just was a question on how to handle this. And it also applies to TextInputPopover, albeit internal it currently relies on labels which mismatch as soon as localization isn't English.

I think _item makes sense - at first it seemed to me as tho it might be insufficient because actions can be re-used, but the same container surely won't have more than one ActionItem.