feat: exponential histogram - part 3 - export

[mwear]

Which problem is this PR solving?

This PR is part 3 in a series of PRs to add exponential histogram support. See this comparison introduced by this PR (omitting those from Part 1 and Part 2).

Partially Fixes #3324

Short description of the changes

This PRs addresses the final details to wire up exponential histogram export to OTLP.

This code is heavily based on the Golang reference implementation. For other details see:

• the metrics data model spec
• the metrics sdk spec
• the metrics protobufs

For the other PRs in this series see:

• Part 1 - The mapping functions
• Part 2 - The accumulation and aggregator
• Part 3 - Wiring up export

You can see all 3 PRs combined in the original draft PR

Type of change

Please delete options that are not relevant.

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

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Extensive unit testing
• End to end test with the 3 PRs from this series adding ExponentialHistogram support

Checklist:

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

[codecov]

Codecov Report

Merging #3506 (da35d43) into main (dbe005f) will increase coverage by 0.04%.
The diff coverage is 75.00%.

❗ Current head da35d43 differs from pull request most recent head 8887055. Consider uploading reports for the commit 8887055 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3506      +/-   ##
==========================================
+ Coverage   93.61%   93.66%   +0.04%     
==========================================
  Files         274      277       +3     
  Lines        8197     8462     +265     
  Branches     1691     1756      +65     
==========================================
+ Hits         7674     7926     +252     
- Misses        523      536      +13     

Impacted Files	Coverage Δ
...tal/packages/otlp-transformer/src/metrics/types.ts	100.00% <ø> (ø)
packages/sdk-metrics/src/view/Aggregation.ts	93.82% <55.55%> (-4.79%)	⬇️
.../packages/otlp-transformer/src/metrics/internal.ts	98.00% <100.00%> (+0.27%)	⬆️
packages/sdk-metrics/src/aggregator/index.ts	100.00% <100.00%> (ø)

... and 3 files with indirect coverage changes

[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 14 days.

[dyladan]

Can probably combine these changelog entries into one more user-friendly one that references both PRs since this release actually makes this feature available.

[dyladan]

Was this a mistake that got through before?

[mwear]

This was an existing issue on main that predates my work on the exponential histogram.

[pichlermarc]

Looks great, thanks for putting in all the effort to implement this. 🙂🚀

[pichlermarc]

Failing tests are unrelated to this PR, see #3700