Minor tweaks + fixes

Dragging an order to the edge of the Workflow screen will now scroll the entire Workflow screen horizontally, allowing you to easily drop orders in statuses that would typically have been displayed off-screen.
Various tweaks and improvements to the
Import Customer
and
Import Supplier
tools
Fixed an issue resulting in the colour dropdown being cut off when adding certain products to orders.
Fixed an issue with the colour dropdown contents not displaying in alphabetical order.
Fixed an issue for Xero customers that caused an order to fail to submit if content from an external website was pasted into a product's description