Feat: New Permission Category Related to Fulfillments

[pevey]

Challenge:

In the admin UI, there is only one set of permissions related to the Order entity.

This encompasses both adding a fulfillment to an order (such as what a warehouse/shipping would do) and modifying/cancelling the order (such as what customer service would do). Currently, the admin UI will error and log you out if you do not have orderUpdate permission and try to add a fulfillment to an order.

Request:

It would be really great if an additional permission category related to order fulfillments were added to specifically address the warehouse/shipping manager role. This role should ideally not have access to modify orders in the way the very powerful order editor component allows. They should only be able to add and edit fulfillments.

On a related note, the Fulfillment and modification links should not appear in the UI if the user does not have the required permission. Right now, the elements appear but cause an error if used. I can work on this by adding the appropriate permission filters in the html template.