[CONFIGURATION] Update registry factory to return a unique_ptr

[dbarker]

Followup from #4367 (comment)

Changes

• Configuration RegistryFactory::Create returns a unique_ptr

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 83.12%. Comparing base (06423fb) to head (c45b436).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4487      +/-   ##
==========================================
- Coverage   83.13%   83.12%   -0.00%     
==========================================
  Files         519      519              
  Lines       20256    20256              
==========================================
- Hits        16837    16835       -2     
- Misses       3419     3421       +2     

Files with missing lines	Coverage Δ
sdk/src/configuration/registry_factory.cc	85.72% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[marcalff]

LGTM