Change from out-of-date smoke-and-mirrors vertical-collection to @html-next

[Owlman145]

We have add-ons that deal with occlusion by using html-next vertical-collection. Frost-list conflicts with that by forcing an old and clunky version of vertical-collection as part of the smoke-and-mirrors package.

Would it not make sense to switch to the up to date @html-next/vertical-collection?

[notmessenger]

FROST-812 is open for exactly this reason but we cannot make this change until after we have upgraded this add-on past Ember CLI 2.12.3. That effort will hopefully begin after we have completed FROST-480 and FROST-806.