Update Backstop scripts after removal of deprecated waitFor()

For context garris/BackstopJS#1441 which says we need to maintain this ourselves

backstop_data/engine_scripts/puppet/clickAndHoverHelper.js

@@ -7,31 +7,31 @@ module.exports = async (page, scenario) => {
 
   if (keyPressSelector) {
     for (const keyPressSelectorItem of [].concat(keyPressSelector)) {
-      await page.waitFor(keyPressSelectorItem.selector);
+      await page.waitForSelector(keyPressSelectorItem.selector);
       await page.type(keyPressSelectorItem.selector, keyPressSelectorItem.keyPress);
     }
   }
 
   if (hoverSelector) {
     for (const hoverSelectorIndex of [].concat(hoverSelector)) {
-      await page.waitFor(hoverSelectorIndex);
+      await page.waitForSelector(hoverSelectorIndex);
       await page.hover(hoverSelectorIndex);
     }
   }
 
   if (clickSelector) {
     for (const clickSelectorIndex of [].concat(clickSelector)) {
-      await page.waitFor(clickSelectorIndex);
+      await page.waitForSelector(clickSelectorIndex);
       await page.click(clickSelectorIndex);
     }
   }
 
   if (postInteractionWait) {
-    await page.waitFor(postInteractionWait);
+    await page.waitForTimeout(postInteractionWait);
   }
 
   if (scrollToSelector) {
-    await page.waitFor(scrollToSelector);
+    await page.waitForSelector(scrollToSelector);
     await page.evaluate(scrollToSelector => {
       document.querySelector(scrollToSelector).scrollIntoView();
     }, scrollToSelector);