feat: Add parentSpanContext to Span and ReadableSpan

[JacksonWeber]

Which problem is this PR solving?

This PR adds the parentSpanContext to the Span and ReadableSpan in order to adhere to the OTel spec.

Targets 1.x OTel, and will be accompanied by a follow-up PR against main with the breaking change of removing parentSpanId.

Fixes #5345

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Existing tests have been updated to include checks for the new parentSpanContext values.

Checklist:

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

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Please upload report for BASE (v1.x@ac8641a). Learn more about missing BASE report.

Additional details and impacted files

@@           Coverage Diff           @@
##             v1.x    #5422   +/-   ##
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  Coverage        ?   94.66%           
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  Files           ?      322           
  Lines           ?     8061           
  Branches        ?     1633           
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  Hits            ?     7631           
  Misses          ?      430           
  Partials        ?        0           

Files with missing lines	Coverage Δ
...kages/otlp-transformer/src/trace/internal-types.ts	100.00% <ø> (ø)
packages/opentelemetry-sdk-trace-base/src/Span.ts	97.63% <100.00%> (ø)
...ackages/opentelemetry-sdk-trace-base/src/Tracer.ts	98.57% <ø> (ø)

[pichlermarc]

We should drop the parentSpanId, but otherwise looks good 🙂

[JacksonWeber]

We should drop the parentSpanId, but otherwise looks good 🙂

Thanks for the review! I'll update the description of the PR, but I discussed with Daniel in the JS SIG - the idea behind this PR is to target the 1.x branch with the non-breaking change of adding the parentSpanContext and I'll create a follow-up PR to target main with the breaking change of removing parentSpanId. The purpose being to get unblocked sooner on having access to the parentSpanContext before the release of the 2.x SDK.

I did not check which branch this is targeting.

[pichlermarc]

@JacksonWeber my bad, did not see that this was targeting v1.x.

@dyladan does that mean that we're going to release a new v1.x feature version?

[JacksonWeber]

@pichlermarc Looks like there might be a perms issue with the W3C integration tests running against v1.x branch.