[BUILD] Build break with external CMake nlohman_json package

[marcalff]

Fixes #2352

Changes

The unit test program otlp_http_log_record_exporter_test depends on nlohman_json.

Because of this, the dependency should be made explicit in CMakeList.tst

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

[codecov]

Codecov Report

Merging #2353 (e1decc5) into main (0eaa794) will decrease coverage by 0.01%.
Report is 1 commits behind head on main.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2353      +/-   ##
==========================================
- Coverage   87.41%   87.39%   -0.01%     
==========================================
  Files         199      199              
  Lines        6018     6018              
==========================================
- Hits         5260     5259       -1     
- Misses        758      759       +1     

see 1 file with indirect coverage changes