Add grpc request and response metadata

[samimusallam]

Fixes #3358

Short description of the changes

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How Has This Been Tested?

I assert span results of a call to a unary method which contains custom metadata in both the request and response.

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

Merging #3386 (5b5441f) into main (897c136) will increase coverage by 0.03%.
The diff coverage is 97.43%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3386      +/-   ##
==========================================
+ Coverage   93.28%   93.31%   +0.03%     
==========================================
  Files         247      247              
  Lines        7352     7387      +35     
  Branches     1512     1518       +6     
==========================================
+ Hits         6858     6893      +35     
  Misses        494      494              

Impacted Files	Coverage Δ
...es/opentelemetry-instrumentation-grpc/src/utils.ts	93.75% <90.90%> (-0.99%)	⬇️
...ry-instrumentation-grpc/src/grpc-js/clientUtils.ts	92.68% <100.00%> (+0.18%)	⬆️
...elemetry-instrumentation-grpc/src/grpc-js/index.ts	92.03% <100.00%> (+0.77%)	⬆️
...metry-instrumentation-grpc/src/grpc/clientUtils.ts	88.73% <100.00%> (+0.49%)	⬆️
...entelemetry-instrumentation-grpc/src/grpc/index.ts	93.79% <100.00%> (+0.52%)	⬆️
...-trace-base/src/platform/node/RandomIdGenerator.ts	93.75% <0.00%> (+6.25%)	⬆️

[samimusallam]

Please let me know if I added the changes to the correct changelog as I see there's another one in opentelemetry-js/experimental :)

[vmarchaud]

Please let me know if I added the changes to the correct changelog as I see there's another one in opentelemetry-js/experimental :)

You shoud move the entry to experimental/changelog.md since the package you modified is in experimental

[samimusallam]

Please let me know if I added the changes to the correct changelog as I see there's another one in opentelemetry-js/experimental :)

You shoud move the entry to experimental/changelog.md since the package you modified is in experimental

Moved

[vmarchaud]

cc @open-telemetry/javascript-approvers if someone have some time to review this :)

[legendecas]

Thank you for working on this!

[legendecas]

LGTM % one nit