New Feature: Add Comment at Order history for Accept or reject withdrawl

[Webroju]

It would be nice if, when a cancellation is accepted or rejected, this were also noted in the order history, just as it is currently when the cancellation is submitted.

[Zwernemann]

@Webroju Implemented in v1.8.0: confirming or rejecting a withdrawal now adds a corresponding comment to the order's status history, consistent with the comment added on submission. Thanks for the suggestion!