chore: Refactor UTM params to stay compliant with standards (#12312)

We were using UTM params on various branding urls which weren't
compliant to standard utm params and hence were ignored by analytics
tooling. this PR ensures that the params stays compliant with defined
standard

ref: https://en.wikipedia.org/wiki/UTM_parameters

## Changes 

- updated utm tags on widget and survey urls
- added utm on helpcenter branding

---------

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/javascript/shared/components/Branding.vue

@@ -33,13 +33,15 @@ export default {
     brandRedirectURL() {
       try {
         const referrerHost = this.$store.getters['appConfig/getReferrerHost'];
-        const baseURL = `${this.globalConfig.widgetBrandURL}?utm_source=${
-          referrerHost ? 'widget_branding' : 'survey_branding'
-        }`;
+        const url = new URL(this.globalConfig.widgetBrandURL);
         if (referrerHost) {
-          return `${baseURL}&utm_referrer=${referrerHost}`;
+          url.searchParams.set('utm_source', referrerHost);
+          url.searchParams.set('utm_medium', 'widget');
+        } else {
+          url.searchParams.set('utm_medium', 'survey');
         }
-        return baseURL;
+        url.searchParams.set('utm_campaign', 'branding');
+        return url.toString();
       } catch (e) {
         // Suppressing the error as getter is not defined in some cases
       }