UI for canceling a line item from an order

[kieckhafer]

UI portion of reactioncommerce/reaction#2382

Users with orders permissions should be able to cancel a line item from an order.

Cancelling a line item or reducing the quantity of a line item before an order has been processed should cause the following.

Reduce the amount of the credit authorization or cancel and reauthorize for the correct amount.
Trigger a Line Item Cancelled event
Send the customer an email and a notification letting them know that an item has been removed from their order.

From Ryan's comment in that ticket:

Cancel line item can work just like returns if you change the button to say cancel. When clicking through on the order before capture.

Link for designs below

Unopened refund panel
https://zpl.io/Z1BR2E7

Nothing selected for refund
https://zpl.io/Z1o9ExU

Items selected for refund
https://zpl.io/Z10oeN1

For reaction core members, all of this is in the orders project if you have the Zeplin app.

Public link to work on orders:
https://scene.zeplin.io/project/58af8900737c137280322bd6

And a public link to work on returns:
https://scene.zeplin.io/project/58af8900737c137280322bd6/screen/59360099e99b7a2f61696c59