Is your feature request related to a problem? Please describe.
There are several very important per-process metrics which are not yet collected by host metrics receiver, for example:

• process thread count
• process open handles count
• process open file descriptor count

These can be considered process golden metrics and are needed for most troubleshooting and trend analysis to make sure there are no threads/handles leaks in the process.

Describe the solution you'd like
Collect and emit at least metrics mentioned above.
The ideal solution - collect more per-process metrics (optionally) - include those which are being collected by leading infrastructure monitoring tools on the market.

Describe alternatives you've considered
I have analyzed per-process metrics collected by such competitor tools like New Relic and Data Dog and their infrastructure agents are able to collect these metrics, however I would like to use OTEL collector as unified agent instead.

Additional context
There is a (great) trend to switch to OTEL host metrics receiver for infrastructure monitoring (ex. Signoz, Splunk Observability, New Relic etc.) and if such tools utilize same host metrics receiver, they will all miss very important and useful metrics making troubleshooting and observability much harder.