chore: add release-please automation

[dyladan]

Release automation from https://github.com/googleapis/release-please

As of now, this will only create release PRs based on conventional commits. It will still be up to maintainers to actually push the release to NPM after it is merged. After we are sure the bot is doing what we are expecting, the github action will be extended to actually push releases to NPM automatically.

Changes:

• Remove version.ts files
• Add version.ts files to gitignore
• Generate version.ts files on precompile step
• Add manifest file to tell release-please what the most recent version of each package is
• Add config file to tell release-please where to find each package
• Change lerna version to "independent"
• root package.json version is no longer relevant since packages could have different versions
• Add release-please github action

[codecov]

Codecov Report

Merging #2393 (a789090) into main (f129138) will increase coverage by 0.51%.
The diff coverage is n/a.

❗ Current head a789090 differs from pull request most recent head 7c57925. Consider uploading reports for the commit 7c57925 to get more accurate results

@@            Coverage Diff             @@
##             main    #2393      +/-   ##
==========================================
+ Coverage   92.14%   92.66%   +0.51%     
==========================================
  Files         120      137      +17     
  Lines        3998     4975     +977     
  Branches      844     1048     +204     
==========================================
+ Hits         3684     4610     +926     
- Misses        314      365      +51     

Impacted Files	Coverage Δ
...ry-exporter-collector/src/CollectorExporterBase.ts	92.15% <0.00%> (ø)
...ation-xml-http-request/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...s/opentelemetry-instrumentation-fetch/src/fetch.ts	96.91% <0.00%> (ø)
...ry-context-zone-peer-dep/src/ZoneContextManager.ts	85.18% <0.00%> (ø)
...mentation-xml-http-request/src/enums/EventNames.ts	100.00% <0.00%> (ø)
.../opentelemetry-exporter-collector/src/transform.ts	88.69% <0.00%> (ø)
...-instrumentation-fetch/src/enums/AttributeNames.ts	100.00% <0.00%> (ø)
...ages/opentelemetry-exporter-collector/src/types.ts	100.00% <0.00%> (ø)
...entelemetry-sdk-trace-web/src/WebTracerProvider.ts	100.00% <0.00%> (ø)
...-sdk-trace-web/src/enums/PerformanceTimingNames.ts	100.00% <0.00%> (ø)
... and 8 more

[vmarchaud]

lgtm (except gha name)

[aabmass]

LGTM 😎

[dyladan]

Waiting on open-telemetry/community#809