Expand primary workitems when creating a new secondary workitem

[davidhaimovich]

As a developer in Visual Studio, I want to task a primary workitem (like Story or Defect) so that I can use the context of code to drive decisions about what tasks I write. When I'm tasking a primary workitem, I want the flow to be quick and easy, without a lot of unnecessary clicking. When the new secondary workitem is hidden, I have an impediment to quick and easy editing.

How to Reproduce:

• Select a node with no children.
• Click the add Task button in the button bar.
• Current Behavior: The Task is added, but the node is not expanded.

  Acceptance Criteria:

Given a primary workitem with no secondary workitems, When I create a new secondary workitem, Then the VS Client creates a new seconary workitem below the selected primary workitem, And the VS Client expands the primary workitem so the new secondary workitem is showing.

[JogoShugh]

Awesome user story description

[JogoShugh]

Next steps:

• Unit test improvements