fix permalink handling to force uniqueueness and rename on product destroy

Fixes #4805
Make migration more tolerant of deleted Variants

This migration bailed for me when it found an old order (before Spree used `acts_as_paranoid`) with a line_item referencing a Variant that no longer existed.

Making the migration use `variant_id` instead of `variant.id` fixed this problem for me, and I suspect will make the migration path smoother for other people who have been using Spree since before the `paranoia` gem.

Fixes #4822
Bump activemerchant to 1.43.1

This should fix spree/spree_gateway#149
Don't assume default variant in JS. Let this be controlled by HTML markup.

Fixes #4849
Downcasing locale for jquery.validate i18n messages

Fixes #4867
Added initSelection to variant_autocomplete

Fixes #4862
Set extract first and last name from CreditCard#name

This is a cherry-pick of https://github.com/spree/spree/commit/910f415c979940096165502b608e25ac211256c7
for 2-2-stable

Fixes https://github.com/spree/spree_gateway/issues/156
Fix pagination for taxons

Fixes #4873
Fixes #4854