Commit Window: Refactor

The view layout is rearranged in order to animate showing the table, which is now shown below the toggle button with the Cancel and Commit buttons sliding down. Additionally, when not showing the table we remove all relevant views from memory.
Rename `populateTableView` to `setupArrayController`

With the previous refactoring the new name is more appropriate.
Disable toggle button in the commit window when animating
Bring the action button back for the commit window

The new layout allows us to place the action button back in its original place when the table is revealed.