Implement Environment Variable Context Propagation carriers in api/in…

[Bhagirath00]

Issue: #7992

This PR implements environmental variable context propagation by adding EnvironmentGetter and EnvironmentSetter carriers to the api/incubator module. This allows the Java SDK to extract and inject trace data through standard environment variables.

Changes

• Added EnvironmentGetter to handle context extraction from environment variables.
• Added EnvironmentSetter to handle context injection for child processes.
• Implemented logic to ensure environment variable keys are handled in the standard uppercase format.
• Added comprehensive unit tests to verify case-insensitive lookups and correct value extraction.

Terminal Screenshots

All new unit tests passed successfully.

Code has been formatted and passed style checks.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: Bhagirath00 / name: Bhagirath (4cfffac, df9a72b)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.20%. Comparing base (fff95e0) to head (df9a72b).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #8074   +/-   ##
=========================================
  Coverage     90.20%   90.20%           
- Complexity     7592     7606   +14     
=========================================
  Files           841      843    +2     
  Lines         22911    22929   +18     
  Branches       2288     2289    +1     
=========================================
+ Hits          20666    20684   +18     
  Misses         1529     1529           
  Partials        716      716           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

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

[Bhagirath00]

Well i think Build are failing!!!