feat: add support for Distributions

[TigerHe7]

Addresses: #101

Summary

Adding support for exporting OpenTelemetry Distribution and Histogram types as Cloud Monitoring API v3 Distributions

Tests

• Tested manually with exporting to personal GCP project
• Updated unit tests

[codecov]

Codecov Report

Merging #125 into master will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #125   +/-   ##
=======================================
  Coverage   94.71%   94.71%           
=======================================
  Files          10       10           
  Lines         303      303           
  Branches       58       58           
=======================================
  Hits          287      287           
  Misses         16       16           

Impacted Files	Coverage Δ
...entelemetry-cloud-monitoring-exporter/src/types.ts	100.00% <ø> (ø)
...lemetry-cloud-monitoring-exporter/src/transform.ts	98.93% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b0865d1...60bfae5. Read the comment docs.

[aabmass]

LGTM, as long as the histogram format is the same!