Implement new runtime metrics

[dashpole]

Part of #5655

Changes:

• Move the configuration options to options.go without modification.
• Implements the metrics defined here: https://github.com/open-telemetry/semantic-conventions/blob/main/docs/runtime/go-metrics.md. These are still disabled by default while it is under development.
• Add unit tests

Notes:

It doesn't implement go.schedule.duration, as the histogram will need some additional work to figure out.

Based on prometheus/client_golang#955 (comment), using go's runtime metrics should is more efficient than reading memstats.

[codecov]

Codecov Report

Attention: Patch coverage is 82.50000% with 21 lines in your changes missing coverage. Please review.

Project coverage is 64.7%. Comparing base (c7fb822) to head (79b1a80).

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #5780     +/-   ##
=======================================
+ Coverage   64.4%   64.7%   +0.3%     
=======================================
  Files        200     201      +1     
  Lines      12540   12643    +103     
=======================================
+ Hits        8084    8190    +106     
+ Misses      4220    4203     -17     
- Partials     236     250     +14     

Files	Coverage Δ
instrumentation/runtime/options.go	100.0% <100.0%> (ø)
instrumentation/runtime/runtime.go	76.7% <79.6%> (+76.7%)	⬆️

... and 2 files with indirect coverage changes