Move ToggleWidget to the correct path and add it to modules.json

Change-Id: I338dfa7068f5c82584eed48f7166ee24c0f84467
Followup 1693435cc3c35: actually add OO.ui.PopupTool

Change-Id: Ia4fae9512c04bb2668088443604197dacb5797c7
Make generic localization utility for lang code keyed objects

Utilize in OO.ui.IconedElement and ve.dm.TemplateSpecModel

Change-Id: I0883a73cb478d4f7509f61aebed2b2957ddb9ce8