Implement new runtime metrics

[dashpole]

trafficstars

Part of https://github.com/open-telemetry/opentelemetry-go-contrib/issues/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 https://github.com/prometheus/client_golang/pull/955#issue-1090830520, using go's runtime metrics should is more efficient than reading memstats.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 85.24590% with 18 lines in your changes missing coverage. Please review.

Project coverage is 65.2%. Comparing base (879727b) to head (79f0b56).

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #5780     +/-   ##
=======================================
+ Coverage   64.9%   65.2%   +0.3%     
=======================================
  Files        202     203      +1     
  Lines      12654   12759    +105     
=======================================
+ Hits        8213    8326    +113     
+ Misses      4210    4190     -20     
- Partials     231     243     +12     

Files	Coverage Δ
instrumentation/runtime/options.go	100.0% <100.0%> (ø)
instrumentation/runtime/runtime.go	79.6% <82.8%> (+79.6%)	:arrow_up:

... and 1 file with indirect coverage changes

[MrAlias]

Waiting to merge so @XSAM can review.

[dashpole]

Working on tests. metrics.Read is being strange during unit testing, and seems to always return the same result.

[dashpole]

I had to add code that allocates memory to ensure the metric actually changes for the refresh test. I ran it locally with -count 10000, and it passes, so hopefully it won't be flaky.

[dashpole]

/gc/heap/allocs:bytes and /gc/heap/allocs:objects don't seem to be populated on windows. I'm investigating

[dashpole]

I think I got the test passing

[MrAlias]

Looks like go mod tidy needs to be run.

[MrAlias]

@XSAM PTAL.

[MrAlias]

@XSAM planning to merge this in an hour or two unless I hear from you otherwise.