Change c-select-many-to-many's itemTitle prop to accept the far item, not the middle item.

[ascott18]

Since c-select-many-to-many is now based on c-select[multiple], it is much easier and makes more sense for this prop to be based on the far item. Some wonky stuff had to be added to maintain compatibility for now, but this should be removed. See function itemText in c-select-many-to-many.

[ascott18]

This somewhat conflicts with the ideas in #314

[ascott18]

New plan: keep this behavior, and make sure we find the "real" middle item if we're displaying a selected item.