File Order source should have an entry in the tree

Current Behavior

The list of file order sources in the job chain configuration expert view is located in the step nodes view in a seperate tab. To edit a file order source it is neccessary to open the step nodes view first.

Desired Behavior

The file order sources should have an item in the tree under the step/nodes entry. Also a button in the main job chain view beside the step/nodes button. Clicking the entry or the button should show the list of file order sources.