Enhance CMake configuration for Rust support and testing; streamlining installation

[KunoVonHagen]

This pull request significantly improves the CMake build system and GitHub Actions release workflow for the fluvio_client_cpp project. The main focus is on automating Rust static library integration with CMake, modernizing the test and packaging setup, and providing robust find_package support for consumers. The workflow now builds and packages the library in a more standard and maintainable way, and CMake configuration is more resilient to source changes and versioning.

CMake Build System Improvements:

• The CMake configuration now builds the Rust static library automatically, detects build type (debug/release), and ensures the library and generated headers are always up-to-date and consistent. It also adds robust error checking for missing or duplicate build artifacts. [1] [2]
• Test executables are conditionally built based on the FLUVIO_CLIENT_CPP_BUILD_TESTS option, and test setup is refactored for maintainability.

Packaging and Installation Enhancements:

• The installation rules now properly export include directories, add a version file, and provide a modern find_package experience for downstream consumers. [1] [2] [3]

CI/CD Workflow Updates:

• The GitHub Actions workflow (.github/workflows/release.yml) is updated to use CMake for building, testing, and packaging, including caching, version extraction, and asset upload improvements. [1] [2]

These changes make the build, test, and packaging process more robust, reproducible, and user-friendly for both developers and consumers of the library.

[stefanDeveloper]

LGTM

[stefanDeveloper]

Please resolve merge conflict.

[maldwg]

Looks good!