chore: Limit the number of articles retrieved by widget (#11095)

The UI displays only six articles, and this update introduces a per_page
parameter to control the number of articles returned per API call. The
value is capped between 1 and 100, with a default fallback if a lower
number is set.

This change is necessary due to high website traffic, where excessive
payloads are returned without adding value.

**Changes:** 
- Add index to status, account_id, portal_id, views.
- Add per_page param in the API.
- Update the code in the frontend to fetch only 6

app/javascript/widget/api/endPoints.js

@@ -103,6 +103,7 @@ const getMostReadArticles = (slug, locale) => ({
     page: 1,
     sort: 'views',
     status: 1,
+    per_page: 6,
   },
 });