DM-33478: Use type hinting when converting to PropertySet

[timj]

There can be a large slowdown in PropertySet creation if PropertySet.set() is called without a type being specified. The Configs know the types of their fields so use those types explicitly.

Problematically, the integer type must still be guessed and therefore should either reimplement the guessing code (without the isinstance check because we know it's an int and we know the field doesn't exist) or call ps.set() explicitly -- this defeats the entire purpose of the optimization. Problematically ps.getAsInt() raises when getting a small integer from a long long entry in the container. Rewriting the C++ code to use ps.getAsInt64() could work but is likely not worth it (there are about 15 calls to fix).

[codecov]

Codecov Report

❌ Patch coverage is 2.38095% with 41 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.58%. Comparing base (9cbe204) to head (e72110f).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
python/lsst/pex/config/convert.py	2.70%	36 Missing ⚠️
tests/test_Config.py	0.00%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #67      +/-   ##
==========================================
- Coverage   86.47%   85.58%   -0.90%     
==========================================
  Files          46       46              
  Lines        3639     3677      +38     
==========================================
  Hits         3147     3147              
- Misses        492      530      +38     

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