Add native histogram support for histogram metrics

[rabenhorst]

This PR exposes native histogram configuration for histogram metrics as flags. Without setting the flags, behavior won't change. Native histograms are only scraped when both Prometheus and the client support it and have it enabled, otherwise classic histograms will be scraped.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] CVE Report (Scanner found CVE and adding report)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation only

Which issue/s this PR fixes

How Has This Been Tested?

Ran ingress-nginx in a local Kubernetes cluster using make dev-env and scraped it with Prometheus with native histograms enabled and disabled.

Checklist:

• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] I've read the CONTRIBUTION guide
• [ ] I have added unit and/or e2e tests to cover my changes.
• [x] All new and existing tests passed.