Refresh error due to double encoding in verticalUrl (#836)

* Fix error after refresh due to double encoding in verticalUrl

- URLSearchParams set() encoded verticalUrl even though it's already encoded since it's extracted from window's URL pathname. updated to append to the param string
- replace() only update the first instance unless a global modifier is used (e.g. this would cause refresh issue on mulilang site for verticalUrl as 'es/help_articles'. updated to replaceAll

J=SLAP-1376
TEST=manual

Launched multilang site with iframe data-path directed to a page with spaces in its names. Confirmed refresh and back/forward nav works accordingly.

Co-authored-by: Yen Truong <ytruong@yext.com>

layouts/html.hbs

@@ -115,12 +115,11 @@
     <script>
       {{#babel}}
       function iframeGetSearchParams() {
-        let params = new URLSearchParams(window.location.search);
-        let verticalUrl = window.location.pathname.substr(1)
-        if (verticalUrl) {
-          params.set('verticalUrl', verticalUrl);
-        }
-        return params.toString();
+        const params = window.location.search.substr(1);
+        const verticalUrl = window.location.pathname.substr(1);
+        return verticalUrl 
+          ? params + '&verticalUrl=' + verticalUrl
+          : params;
       }
       let iframeLoadedResolve;
       window.iframeLoaded = new Promise(resolve => {

static/js/iframe-common.js

@@ -15,9 +15,6 @@ export function generateIFrame(domain, queryParam, urlParam) {
     var paramString = window.location.search;
     paramString = paramString.substr(1, paramString.length);
 
-    // Decode ASCII forward slash to avod repeat encodings on page refreshes
-    paramString = paramString.replace("%2F", "/");
-
     // Parse the params out of the URL
     var params = paramString.split('&'),
                  verticalUrl;