Adapt integration tests to Conan 2.0

Summary

The cpplib integration tests cannot be compiled with the cpplib using Conan 2.0 (0.3-dev) due to several issues with the build process.

Specifications

• Version: 0.3-dev
• Platform: Fedora 39, Conan 2.0,

Possible fixes

This requires several changes to

conanfile.txt

CMakeLists.txt

• Remove conan_basic_setup and references to CONAN_LIBS etc.

test/CMakeLists.txt

• Replace ${CONAN_LIBS_GTEST} etc. with real lib references

.docker/Dockerfile \

• Remove $(conan inspect --raw version .. for version determination
• adjust to new conan create
• use conan build instead of cmake --build, or maybe even the Makefile so we don't have to change it here every time