Process Metrics (Top 10)

**Is your feature request related to a problem? Please describe.**

We have to always know what processes to be monitored with the current [process log based metrics](https://docs.fluentbit.io/manual/pipeline/inputs/process) in Fluent Bit in advance. However one of the use cases in the production operation is we'd like to identify what process(es) are consuming more resources. Today, we have to specify a specific process to monitor.
The other way of saying is when there is an issue, we don’t necessarily know what the process is that we want to monitor, log based metrics requires this to be known in advance.

**Describe the solution you'd like**
There has been always greater if fluent bit can get metrics for the top processes, for example if CPU is > 90% on a server, it'll allow people to identify which process(es) are consuming the most CPU and it'll reduce MTTI.

**Additional Notes**
As a reference, this is similar to one in the prometheus node_exporter https://github.com/prometheus/node_exporter/blob/master/collector/processes_linux.go