FilteredConnection: Split out generic UI components

Created by: umpox

Splits out the UI elements from <FilteredConnection /> into their own, exported, components.

This means we can compose FilteredConnection using UI elements and the useConnection hook.

It also means that we can continue refactoring to use useConnection whilst maintaining the same UI and design that we currently have. Although in many places we won't want to continue to use these elements (e.g. areas where we show a custom summary, areas where we hideSearch and so on.).