Remove include of product filter on spree taxons

I don't know what these used to do, but they don't do that anymore.

Fixes #4861
Added initSelection to variant_autocomplete

Fixes #4862

Conflicts:
	backend/app/assets/javascripts/spree/backend/variant_autocomplete.js.erb
add spree.t with translations instead of t

remove spree.t with must_match_order_currency in ensure_proper_currency method