Added Conan Packaging

[LoeschMaximilian]

Hi,

here is a conanfile.py for packaging this project.
Included in this PR are also some minor changes to the build-system. These were required in order to get the tests to compile and give the option to skip the tests.
Please check if it still builds on your end.
The test_package folder includes a small example how to use this new package and it is used to check the validity of the package.
The package requires a very recent version of boost, as it is one of the few, with a Conan v2 recipe like this one. This may be fine-tuned later.

May I also contribute a modified version of this recipe to conan-center?

kind regards,

Max

[RobinQu]

@ybainier Can we merge this, so that it's available through conan.