Possibly re-add collection item to refer to html/jsx attributes

[AndreasArvidsson]

Disabled here
#2039

Can only be done once we have migrated collection item to a proper scope handler. And even then I'm not one hundred percent sure this is the right direction.

[pokey]

I think the argument is that if we support key and value, the pair should be item. But I don't feel super strongly. Let's revisit once it's actually possible

[AndreasArvidsson]

Probably reasonable