Indices management pagination should also be at header

When managing index sets where the lists are paginated, the page navigation should also be at the top of the list of index sets. Additionally it is somewhat confusing when you need to scroll to the bottom to change the page, the content dynamically updates, but the scroll remains at the bottom of the page.


1. Pagination Navigation should be at the top of the lists as well. If you know the set is on another page, it's a waste of time to scroll to the bottom to change pages.
2. When navigating from the bottom of the page, it should scroll back up to the top automatically.
3. It would be nice to be able to customize the viewable list. Unless there's a performance issue, it would be preferable to have one large list of index overviews.

* Graylog Version: 3.0.1