[RFC] Poc config yaml

[marcalff]

Fixes #2481

Request For Comments (Proof of concept code for now)

Start with examples/yaml/main.cc

Features implemented:

• https://github.com/open-telemetry/opentelemetry-configuration
  • Full support for propagators
  • Full support for traces, including recursive sampler definitions.
• Extension points
  • Custom propagators
  • Custom samplers
  • Custom span processors
  • Custom span exporters

Changes

Please provide a brief description of the changes here.

For significant contributions please make sure you have completed the following items:

• [ ] CHANGELOG.md updated for non-trivial changes
• [ ] Unit tests have been added
• [ ] Changes in public API reviewed

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 87.61%. Comparing base (497eaf4) to head (2c15009). Report is 115 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2518      +/-   ##
==========================================
+ Coverage   87.12%   87.61%   +0.49%     
==========================================
  Files         200      190      -10     
  Lines        6109     5874     -235     
==========================================
- Hits         5322     5146     -176     
+ Misses        787      728      -59     

Files	Coverage Δ
sdk/include/opentelemetry/sdk/resource/resource.h	100.00% <100.00%> (ø)
sdk/src/resource/resource.cc	96.78% <100.00%> (+0.48%)	:arrow_up:

... and 123 files with indirect coverage changes