fix: CMake package and imported library target names

[ta7mid]

This PR addresses the following issues encountered/noted when creating a Homebrew formula for reflect-cpp:

• Building with libbson ≥2.0.0 fails as the names of their CMake config package and imported targets were changed.
• In CMakeLists.txt, reflect-cpp links with arrow::arrow when REFLECTCPP_USE_VCPKG is false, but no such target is provided by the CMake config packages installed with Apache Arrow ≥21.0.0, regardless of whether vcpkg is used.
• Generator expressions used to specify interface link libraries (as in target_link_libraries(reflectcpp PUBLIC $<IF:$<TARGET_EXISTS:…>…,…>) are not evaluated and get copied verbatim into the exported reflectcpp-exports.cmake.
• It seems appropriate to link with shared versions of libbson and Arrow when building reflect-cpp as a shared library.

[gemini-code-assist]

Summary of Changes

Hello @ta7mid, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request refines the CMake build system for reflect-cpp to enhance compatibility with updated versions of external dependencies, specifically libbson (2.0.0+) and Apache Arrow (21.0.0+). It addresses breaking changes in how these libraries expose their CMake packages and targets, ensuring reflect-cpp can correctly find and link against them. The changes also streamline the selection between static and shared library linkage based on the project's build type, improving overall build robustness.

Highlights

• libbson CMake compatibility: Updated CMake configuration to correctly identify and link with libbson versions 2.0.0 and newer, which introduced changes to their package and target names. This includes conditional logic for vcpkg usage and explicit static/shared linkage.
• Apache Arrow CMake targets: Adjusted the linking strategy for Apache Arrow to explicitly use Arrow::arrow_static or Arrow::arrow_shared targets, resolving issues with the arrow::arrow target no longer being provided in newer Arrow versions (>= 21.0.0).
• Shared library linkage preference: Implemented logic to prioritize linking against shared versions of libbson and Apache Arrow when reflect-cpp is configured to build as a shared library, ensuring consistent build behavior.
• vcpkg Arrow configuration: Modified vcpkg.json to disable default features for the arrow dependency, providing more precise control over its build configuration and preventing potential conflicts.

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[gemini-code-assist]

Code Review

This pull request addresses several issues with dependency handling in CMake for libbson and Apache Arrow. The changes correctly adapt to new package and target names in recent versions of these libraries and simplify the logic for linking static or shared variants. My main concern is with the version range specified for libbson, which is too restrictive and would prevent using versions newer than 2.0.0. I've left specific suggestions to address this in the code.

[liuzicheng1987]

@ta7mid thanks for the PR.

However, it appears that this has broken the Conan build. Could you take another look?

[ta7mid]

@liuzicheng1987 Can you check if it works now?

[liuzicheng1987]

@ta7mid , there still appear to be the same issue with Conan...

[ta7mid]

It's probably fixed now.