Pass parentNode now we use LayoutManager

Everything is 1 div further these days... Makes this kinda ugly but it
works.

Also set the scrollThreshold to 1 so we only scroll when we hit the
absolute bottom of the page.
Refactored the scrollThreshold calculation
Apparently browsers don't all behave identically

Infinite Scroll on the document needs to find scrollHeight from
different attributes depending on the browser.
Empty searches dont make sense for library

...unlike in places
Removed unused code

Only configure infinite scroll once
Library ItemCollection to MoxieCollection

Added the ongoingFetch attribute also.
Library search show loading spinner

Also a message if we have no results.
Fix add results to SearchView on infinite scroll

onClose -> cleanup