fixes #2241 clear up confusion about currentApp actually being stored ap...

...p, and use locale app where possible and where it makes sense
We use it right here: https://github.com/mozilla-appmaker/appmaker/pull/2297/files#diff-5cf414fc7841f6eb1423d615cadcf6d2R793

And I believe that's a link to open the actual app, to show which app is currently saved in storage. I left the classname as is as I felt it was no longer a variable storing a name, but a functional link to the app itself.