Display the number of change requests in the "Change Request" tab of the page extra area

The "Change Request" tab in the page extra area gives no indication of how many change requests exist for the current page. Users have to open the tab to discover them, which reduces the visibility of ongoing change activity on a page.

Proposal of inprovement: Display the number of change requests for the page in parentheses in the tab label, similar to how the "Attachments" tab (https://www.xwiki.org/xwiki/bin/view/Documentation/UserGuide/Features/Attachments#HUsingtheattachmenttabatthebottomofthepage) shows the number of attachments, e.g. Change Request (1).