feat: Add settings for cpu/mutex/block profiling options

[chaudum]

What this PR does / why we need it:

The HTTP endpoints for scraping CPU, mutex and block profiles are already exposed by the server, however, block and mutex profiling must be explicitly enabled by setting a non-zero value for SetBlockProfileRate and SetMutexProfileFraction respectively.

For more information about the available options consult the Go documentation:

• https://pkg.go.dev/runtime#SetBlockProfileRate
• https://pkg.go.dev/runtime#SetMutexProfileFraction
• https://pkg.go.dev/runtime#SetCPUProfileRate

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR