Rework native library

[markaren]

A first attempt to rework the native library.

• PyState needs to be checked.
• setup_experiment is removed (API change).
  • startTime is moved to enter_initiliaization_mode`
• Fix logging possibly overriding importers debug request.
  • debug parameter to 'log' has no longer any effect and a warning is emitted on use
• Fixes and enables disabled logging tests

This change should make it easier to understand the native workings and also make it easier to add FMI3 support. The structure is similar to fmu4cpp.

[Copilot]

Pull Request Overview

This PR reworks the native library by refactoring core FMU functions, improving logging behavior and error handling, and updating API usage for greater clarity and support for FMI3 in the future.

• Refactored fmi2.cpp to replace reinterpret_cast with static_cast and improved logger usage.
• Updated PySlaveInstance implementation and removed deprecated setup_experiment.
• Removed legacy cppfmu_cs files and updated log message formatting.

Reviewed Changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pythonfmu/fmu_except.hpp	New exception class added for fatal errors.
pythonfmu/fmi2.cpp	Refactored casting, logging, and FMI function implementations.
pythonfmu/SlaveInstance.hpp	Updated interface for SlaveInstance with optional parameters.
pythonfmu/PySlaveInstance.{hpp,cpp}	Reworked Python slave instance integration with improved resource handling.
pythonfmu/Logger.hpp	Introduced a new PyLogger interface for consistent logging.
pythonfmu/cppfmu/cppfmu_cs.{hpp,cpp}	Legacy co-simulation interface removed.
pythonfmu/logmsg.py	Adjusted LogMsg class and its string formatting.
pythonfmu/fmi2slave.py	Minor API changes in initialization mode and logging support.
pythonfmu/_version.py	Version bumped to 0.7.0.

Files not reviewed (1)

• pythonfmu/pythonfmu-export/src/CMakeLists.txt: Language not supported