Iglistkit: IGListSingleSectionControllerDelegate selection function should include object

[rnystrom]

Right now to get the object from the selectionDelegate, you have to:

func didSelect(_ sectionController: IGListSingleSectionController) {
  let object = adapter.object(for: sectionController)
  // do something
}

When IGListSingleSectionController already has the object, this lookup is wasteful.

I propose we change the delegate method to:

- (void)didSelectSingleSectionController:(IGListSingleSectionController *)sectionController 
  withObject:(id)object;

• What do you think about the naming? "withObject" or maybe just "object"?
• Should we shorten the method to just didSelectSectionController?

[Sherlouk]

For the Swift interop it would be nice for something like didSelect(_ sectionController: .. with object: ..)

If no one else takes it, I may give this a try?

reminder