Implement OTEL_SDK_DISABLED

[marcalff]

Fixes #1631

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

[netlify]

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

Name	Link
🔨 Latest commit	624fdc7
🔍 Latest deploy log	https://app.netlify.com/sites/opentelemetry-cpp-api-docs/deploys/678c2bf6ce9e4d0008961bf3

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 87.83%. Comparing base (25f7a13) to head (624fdc7).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3245      +/-   ##
==========================================
+ Coverage   87.78%   87.83%   +0.06%     
==========================================
  Files         198      202       +4     
  Lines        6308     6334      +26     
==========================================
+ Hits         5537     5563      +26     
  Misses        771      771              

Files with missing lines	Coverage Δ
api/include/opentelemetry/logs/provider.h	100.00% <100.00%> (ø)
api/include/opentelemetry/metrics/provider.h	100.00% <ø> (ø)
api/include/opentelemetry/trace/provider.h	100.00% <ø> (ø)
exporters/ostream/test/ostream_log_test.cc	96.18% <100.00%> (ø)
sdk/src/common/disabled.cc	100.00% <100.00%> (ø)
sdk/src/logs/provider.cc	100.00% <100.00%> (ø)
sdk/src/metrics/provider.cc	100.00% <100.00%> (ø)
sdk/src/trace/provider.cc	100.00% <100.00%> (ø)