* feat(list-view): Adds the ability to check whether or not an Item at index is Visible on screen within a listView
* feat(list-view): add the unit-test for checking if list-item is visible.
* clean(list-view): fix invalid reference in list-view-common
* chore(list-view): remove unused logic
* test(list-view) updates the tests for checking if item at index is visible
* chore(ListView Tests): update the test_check_if_item_at_index_is_visible unit test to include 40 children, and test if the last item is visible or not.
* Chore(ListView IOS): Apply requested changes to the for-loop, and replace with Array.some for readability.
* chore(ListView android): Fix TSLint issues.