<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description
This PR adds obs for logs in scraper/scraperhelper, also introduced new
metrics for scraping logs.
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#### Link to tracking issue
Relates to #11238
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#### Testing
Added
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#### Documentation
Added
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Chao Weng
Bogdan Drutu