Make auto_capture? a per payment configuration

Fixes #4302
Do not use orders_per_page to determine amount of zones returned in Admin::ZonesController

Fixes #4305
Display 'Capture events' table in the Payment show page

Fixes #4301
Allow stock items to only touch their variant after save if their in_stock state changes

Currently when a stock item changes its count on hand (e.g. an order is placed), it touches the related variant, which touches its related product (thus invalidating product cache). For users that do not show inventory counts on their product page, this code enables the ability to keep product page cache warm until a stock item changes its in_stock state, rather than on every purchase of that stock item.

Fixes #4299
Duplicate variants when duplicating products

Fixes #4029
Fixes #4264
Added rescue block in UpgradeAdjustments migration to catch issues where calculators no longer exist

Fixes #4274
Fixes #4278
Add script to backend so rails g can run