Add a local graph view to the Starting Material edit page

[jdbocarsly]

The local graph view is currently shown in Samples, Cells, and Collections, but not Starting Materials

[ml-evs]

This is a good idea (maybe one place that this graph view is actually very useful) but we might need to revise our default settings for the item graph, since adding "lithium" will blow up quite quickly once it gets further out than one node. See also the bug I ran into when creating a manager account which seems to display all nodes in the local item graph (#629)