Woocommerce-admin: Task list - group tasks

[jameskoster]

I've been playing with the task list feature for a while now and feel quite strongly that we should visually group complete / incomplete tasks. The zebra striping effect that occurs if you work through tasks in "the wrong order" is a bit disorientating. This issue will become more prominent when we implement the more aggressive smart defaults we've been talking about to preconfigure tasks.

Ordering the tasks this way will also be beneficial for folks who navigate via keyboard or screen-reader, to have quicker access to incomplete tasks as well.

[joshuatf]

We can pretty easily sort by the completed property in tasks in getAllTasks.

Estimate: 1