Move CXCppInterOp.h to CppInterOp folder

[mcbarton]

As we are removing the clang/Interpreter/CppInterOp.h as part of CppInterOp v2.0, it didn't make sense to me to have a clang-c folder, so this PR moves the CXCppInterOp.h header file under the CppInterOp folder

[vgvassilev]

Hi @mcbarton, as I've mentioned -- we are in a sprint and moving quickly. This should be handled by #921

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.82%. Comparing base (61e4c60) to head (4cbbb27).
⚠️ Report is 109 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #935   +/-   ##
=======================================
  Coverage   80.82%   80.82%           
=======================================
  Files          15       15           
  Lines        4710     4710           
=======================================
  Hits         3807     3807           
  Misses        903      903           

Files with missing lines	Coverage Δ
lib/CppInterOp/CXCppInterOp.cpp	50.28% <ø> (ø)

Files with missing lines	Coverage Δ
lib/CppInterOp/CXCppInterOp.cpp	50.28% <ø> (ø)

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.