Use body.dataset.page for Internal Events category value in Frontend

What does this MR do and why?

Currently we are using InternalEventsTracking as a category for Internal Events. Instead of that we are now using category as location on where the event happened. Which is default when no category is provided.

MR acceptance checklist

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How to set up and validate locally

We can verify the category for existing tracking.

1. In GDK go to http://127.0.0.1:3000/admin/dev_ops_reports
2. Click on the dev tab, Verify Category is admin:dev_ops_report:show which used to be InternalEventTracking before.

Related to #435199 (closed)