Add Tabs connected to ViewPager

Should be fairly simple to connect the ViewPager to tabs like is done here: https://github.com/madhu314/react-native-tabbed-view-pager-android

The above library is out of date and it uses a broken version of ViewPager. We could offer tabs as optional and nice to have.

[Kristonitas]

I just found a way to do it out of the box.

const Tabs = () => {
  const [pageIndex, setPageIndex] = useState(0);

  let viewPager;

  const tabsRef = node => {
    if (node !== null) {
      viewPager = node;
    }
  };

  const setPage = (index: number) => {
    setPageIndex(index);
    viewPager && viewPager.setPage(index);
  };

  const onPageSelected = ({ nativeEvent: { position } }: PageSelectedEvent) => {
    setPageIndex(position);
  };

  return (
    <>
      <ViewPager
        initialPage={0}
        ref={tabsRef}
        onPageSelected={onPageSelected}
      >
        <View key="0">
          <Screen text="A" />
        </View>
        <View key="1">
          <Screen text="B" />
        </View>
      </ViewPager>
      <PageButtons currentIndex={pageIndex} setPage={setPage} />
    </>
  );
};

[troZee]

Closing bc tabview is responsible for adding tabs on top of pager view. More here https://github.com/satya164/react-native-tab-view#readme