Create a scraper status page

[grossir]

Let's track here our ideas and requirements for a "scraper status page". Sometimes scrapers fail (for many reasons) and such a page would be useful to notice more errors that won't surface on Sentry

Background

In #3949 we deleted cl/scrapers/management/commands/cl_report_scrape_status.py which depended on the ErrorLog model and created a useful HTML report, that was sent via email and also to a slack channel

However, it seems nobody was really monitoring that, and both the content and the access to the report could be improved

Ideas

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