Feature request - Support pagination on both sides of the list.

[srameshr]

Could you try to support pagination on either side of the list? More explanation here: facebook/react-native#20500

Use case:

1. For records from 0 to 100, you load records from 45 to 55 to the UI on the first mount of the component and render 50th element to the user's view.
2. On scroll left or up obtain records from 44 to 35 and prepend to the list.
3. Vice versa for scroll right or down.