feat: Add new baggage span processor package

[MikeGoldsmith]

Which problem is this PR solving?

Adds new baggage span processor as discussed in the following issue:

• Closes Request for new component: Baggage Span Processor #2104

I've added to /packges directory - let me know if you'd prefer it somewhere else.

Short description of the changes

• Adds new baggage span processor package

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.12%. Comparing base (dfb2dff) to head (ae60cae).
Report is 103 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2114      +/-   ##
==========================================
+ Coverage   90.97%   95.12%   +4.14%     
==========================================
  Files         146       10     -136     
  Lines        7492      697    -6795     
  Branches     1502      143    -1359     
==========================================
- Hits         6816      663    -6153     
+ Misses        676       34     -642     

see 137 files with indirect coverage changes

[Flarna]

I think .github/component_owners.yml should be also updated
Not 100% sure about .github/component-label-map.yaml and release-please-config.json

Usually the opentelemetry- prefix for the folder is not used anymore for new stuff (see winston-transport).

[MikeGoldsmith]

Thanks for the review @Flarna - I've updated the directory structure and fixed the readme title.

[MikeGoldsmith]

Thanks for the suggestions @hectorhdzg - I've made some updates. Let me know what you think.

[JamieDanielson]

Thanks @MikeGoldsmith ! I've added a few suggestions for changes.

[JamieDanielson]

We'll also want to add to release-please-config.json based on the one check:

Could not find "packages/baggage-span-processor" entry in release-please-config.json. If you are adding a new package. Add following to "packages" object
"packages/baggage-span-processor": {},

[MikeGoldsmith]

Thanks for review @JamieDanielson - I've worked through your feedback and suggestions. I think this is ready for another review.

[hectorhdzg]

LGTM

[blumamir]

I think many users can benefit from this capability, thank you.

Added 2 non-blocking suggestions / discussions which I think might worth consideration so that we don't end up introducing breaking changes in the future or promoting something that might be unsafe by default.

@MikeGoldsmith current PR already add a useful feature so let me know if you prefer not to address those at the moment.

[MikeGoldsmith]

@Flarna @hectorhdzg @blumamir Is there anything else you would like to see before this PR is accepted?

[MikeGoldsmith]

Ping @open-telemetry/javascript-maintainers - looking for further feedback on this PR.