[fix] ScrollView dependency on 'style' forwarding for sticky headers

Not every item that may be rendered by a ScrollView will forward 'style', so cloning the item element is not safe. Instead, we can wrap the item in a 'View' and apply the styles for the sticky header to this element.

Close #1175

packages/react-native-web/src/exports/ScrollView/index.js

@@ -168,7 +168,7 @@ const ScrollView = createReactClass({
       !horizontal && Array.isArray(stickyHeaderIndices)
         ? React.Children.map(this.props.children, (child, i) => {
             if (child && stickyHeaderIndices.indexOf(i) > -1) {
-              return React.cloneElement(child, { style: [child.props.style, styles.stickyHeader] });
+              return <View style={styles.stickyHeader}>{child}</View>;
             } else {
               return child;
             }