[SDK] Create instrumentation scope library

[dbarker]

Contributes to #1429

Changes

• moves instrumentation_scope.h impl to instrumentation_scope.cc and creates library targets with CMake and Bazel

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]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.87%. Comparing base (e79ab1f) to head (6b496fa).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4351      +/-   ##
==========================================
+ Coverage   80.85%   80.87%   +0.02%     
==========================================
  Files         450      451       +1     
  Lines       19215    19223       +8     
==========================================
+ Hits        15535    15545      +10     
+ Misses       3680     3678       -2     

Files with missing lines	Coverage Δ
...y/sdk/instrumentationscope/instrumentation_scope.h	100.00% <ø> (ø)
.../src/instrumentationscope/instrumentation_scope.cc	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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