Editable fulfillment method and tracking code.

[dlhck]

Migrated from #589

Is your feature request related to a problem? Please describe.
Once the fulfillment method and tracking code and submitted, it's not possible to edit them. It would be a good feature to be able to edit them for 3 reasons.

1. The obvious one where a mistake is made.
2. For some reason, the tracking code/method is to be changed. Ex. Issues with logistics company for the particular order.
3. For using to track the return order.

Describe the solution you'd like
Make the fulfillment method and tracking code editable. And enable history logging the event, this will help keep a track of things in the long run.

Describe alternatives you've considered

Additional context
Add any other context or screenshots about the feature request here.