feat: Add dd-win-prof as a dependency, built on Windows when DD_ENABLE_PROFILER=ON

[awforsythe]

This PR integrates dd-win-prof into the SDK's CMake build, allowing it to be included and built as a dependency when DD_ENABLE_PROFILER is set and the SDK is being built for Windows.

As of this PR, on a Windows VM, from a fresh copy of dd-sdk-cpp, I can configure and build with -DDD_ENABLE_PROFILER=ON:

cmake^
  -DDD_DEVELOPMENT=ON^
  -DDD_CRASH_MODE=inprocess^
  -DDD_ENABLE_CLANG_TIDY=OFF^
  -DDD_ENABLE_CLANG_FORMAT=OFF^
  -DDD_ENABLE_COVERAGE=OFF^
  -DDD_ENABLE_SANITIZERS=^
  -DDD_HTTP_USE_SYSTEM_LIBCURL=OFF^
  -DDD_ENABLE_PROFILER=ON^
  -S . -B build && cmake --build build --config Release

The dd-sdk-cpp CMake project will pull in dd-win-prof via FetchContent (temporarily using branch aforsythe/cmake), build it from source, and add it as a dependency of dd-sdk-cpp, such that we could include dd-win-prof headers and call its public functions from the SDK.

Additionally, the datadog_enable and datadog_install convenience functions (used to add Datadog SDK support to downstream projects, like the example dd_native_repl program) now handle copying dd-win-prof.dll and datadog_profiling_ffi.dll to the final output directory.

So once our CMake build completes, we have an example program with all required artifacts in place:

C:\dd\dd-sdk-cpp>dir /b build\examples\Release
datadog_profiling_ffi.dll
dd-win-prof.dll
dd_native_cpp_example.exe
dd_native_c_example.exe
dd_native_repl.exe

This PR does not attempt to integrate dd-win-prof into the SDK, nor does it add any calls to dd-win-prof's API. This PR is concerned only with ensuring that we can build dd-win-prof seamlessly alongside the SDK.

[fuzzybinary]

This probably doesn't have too be pulled into main -- we can leave this on an experimental branch so long as the Profiling team knows how to get it.

The base branch was changed.

[datadog-datadog-prod-us1]

✅ Code Quality    ✅ Code Vulnerabilities    ✅ Library Vulnerabilities    ✅ Secrets

🎉 All green!

🛠️ No new code quality issues
🛡️ No new code vulnerabilities
📚 No new vulnerable libraries detected
🔑 No new secrets detected

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[awforsythe]

This branch has been supplanted by the profiling team's more recent work; closing this PR in favor of #185.