[CONFIGURATION] File configuration - zipkin exporter builder

[marcalff]

Contributes to #2481

This is a partial fix, to implement the zipkin exporter builder.

Changes

Please provide a brief description of the changes here.

• Add a new option constructor, that ignores environment variables
• Implement the zipkin exporter builder

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

[netlify]

✅ Deploy Preview for opentelemetry-cpp-api-docs canceled.

Name	Link
🔨 Latest commit	31c2036
🔍 Latest deploy log	https://app.netlify.com/projects/opentelemetry-cpp-api-docs/deploys/688713a3d8f24d0009d9d9d9

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.06%. Comparing base (f993e96) to head (31c2036).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3565      +/-   ##
==========================================
+ Coverage   90.03%   90.06%   +0.03%     
==========================================
  Files         220      220              
  Lines        7069     7069              
==========================================
+ Hits         6364     6366       +2     
+ Misses        705      703       -2     

see 2 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[dbarker]

Looks good. Thanks!