Keep UI in sync with current step while using Undo/Redo

[aarondr77]

Keep the UI in sync with the current step. For example, if you have two sheets and you applied a column to the first sheet and then applied a column to the second sheet. If you press Undo twice, you will still have the second sheet selected, even though the Undo didn't touch the second sheet. This makes it difficult to understand the effect of your Undo! Similarly, if you undo back to a pivot table, for example, the pivot table taskpane should open so you can edit the step. On the other hand, the UI moving around could be confusing, so we will want to usability test this.