Update paginator logic to not render "..." separator as a link.

[eliotjordan]

Follow on to #149.

The "..." paginator separators are currently rendered as links which do not trigger paginate events:

dpul-collections/lib/dpul_collections_web/live/search_live.ex

Lines 209 to 210 in 36c66f6

	type == :pre -> [{page, false}, {"...", false}]
	type == :post -> [{"...", false}, {page, false}]

dpul-collections/lib/dpul_collections_web/live/search_live.ex

Line 172 in 36c66f6

def handle_event("paginate", %{"page" => page}, socket) when page != "..." do

It would be better if these were rendered as a span or div or some other element.