Expose additional resource utilization metrics on /metrics endpoint

## Overview

As a node-runner, I would like to have additional resource utilization metrics exposed on the /metrics endpoint, so that I am able to better track the resource utilization that Algod uses and establish alerts on them

## Details

- Metrics to expose:
- `process_open_fds` (to track open file descriptors)
- `process_max_fds` (to track the max file descriptors available)
- `process_cpu_seconds_total` (to track total user and system CPU time spent in seconds, type: counter)
- `process_resident_memory_bytes` (to track resident memory size in bytes, type: gauge)

## Example Cases:
- [Alerting on approaching open file limits](https://www.robustperception.io/alerting-on-approaching-open-file-limits/)
#3185

## Potential Approach
- Add `func newProcessCollector` to our own algod implementation such that the /metrics endpoint can report algod's own process metrics
- https://pkg.go.dev/github.com/prometheus/client_golang/prometheus/collectors#NewProcessCollector