Fix the position of the ViewInApp popup while scrolling (#494)

src/ensembl/src/shared/components/view-in-app-popup/ViewInAppPopup.scss

 @import 'src/styles/common';
 
+.wrapper {
+  position: relative;
+}
+
 .pointerBox {
   padding: 6px 12px;
   background: $black;

src/ensembl/src/shared/components/view-in-app-popup/ViewInAppPopup.tsx

@@ -34,11 +34,12 @@ const ViewInAppPopup = (props: ViewInAppPopupProps) => {
   const anchorRef = useRef<HTMLSpanElement>(null);
 
   return (
-    <span ref={anchorRef} onClick={() => setShowPointerBox(!showPointerBox)}>
+    <span className={styles.wrapper} ref={anchorRef} onClick={() => setShowPointerBox(!showPointerBox)}>
       {children}
       {showPointerBox && anchorRef.current && (
         <PointerBox
           anchor={anchorRef.current}
+          renderInsideAnchor={true}
           onOutsideClick={() => setShowPointerBox(false)}
           position={props.position}
           autoAdjust={true}