move cache metrics inc to orchestrator
Currently, we calculate cache metrics in a job that runs every X minutes but this one queries the full cache collection every time leading to mongo query targeting issues in Mongo Atlas (ratio > 1000).
 
The ratio of documents scanned to returned exceeded 1000.0 on  datasets-server-prod-shard-00-00.ujrd0.mongodb.net, which typically suggests that un-indexed queries are being run.  To help identify which query is problematic, we recommend navigating to the Query Profiler tool within Atlas. Read more about the Profiler here.

![Screenshot from 2023-08-09 08-28-05](https://github.com/huggingface/datasets-server/assets/5564745/30b14c57-757b-42f6-916b-93f55bd46840)


In order to avoid this alert, this PR moves the metrics increase to orchestrator so that, every time a cache in recorded, it will update the metrics collection as well..

Caveats: 

- There is no way to "decrease" the counters if a cache record is deleted. It could be implemented when doing the delete but It could increase db load.
move cache metrics inc to orchestrator: Currently, we calculate cache metrics in a job that runs every X minutes but this one queries the full cache collection every time leading to mongo query targeting issues in Mongo Atlas (ratio > 1000).
 
The ratio of documents scanned to returned exceeded 1000.0 on  datasets-server-prod-shard-00-00.ujrd0.mongodb.net, which typically suggests that un-indexed queries are being run.  To help identify which query is problematic, we recommend navigating to the Query Profiler tool within Atlas. Read more about the Profiler here.

![Screenshot from 2023-08-09 08-28-05](https://github.com/huggingface/datasets-server/assets/5564745/30b14c57-757b-42f6-916b-93f55bd46840)


In order to avoid this alert, this PR moves the metrics increase to orchestrator so that, every time a cache in recorded, it will update the metrics collection as well..

Caveats: 

- There is no way to "decrease" the counters if a cache record is deleted. It could be implemented when doing the delete but It could increase db load.