feat(lxc_manager): refactor to use io_uring, smart pointers, and atomics

This commit refactors the LxcManager class and its dependencies to improve resource management, thread safety, and asynchronous I/O handling.

Key changes include:

• io_uring Integration: The project now depends on liburing for efficient asynchronous I/O operations. The CMake build system is updated to find and link this library.
• Resource Management: The ContainerSession struct now uses a std::unique_ptr with a custom deleter (lxc_container_put) for the LXC container. This ensures automatic and safe resource cleanup, preventing memory leaks.
• Concurrency: Session ID generation is made thread-safe by using std::atomic<SessionId>. A new std::atomic<bool> flag is introduced to manage the io_uring thread's lifecycle more safely.
• Code Simplification: The LxcManager's internal logic is streamlined by removing redundant helper functions and a manual user data pool.
• Improved Logging: Standard output and error streams are replaced with spdlog for more robust and configurable logging.
• Build System: The CMake file is updated to use standardized source file paths and properly link against the new liburing dependency.