Edit activity name inline does not update activity grade item

If you edit an activity's name with the inline editing (new edit title widget) then the associated activity grade item name is not updated.

Normally the grade item is updated through "modname_grade_item_update" callback, though I don't know if it is appropriate to call this here. The alternative is to try to update the grade item directly, though I do believe it is possible for an activity to have multiple grade items.