Hiding the public classes or the exceptions of this project would render
libcanbustoolbox.so unusable, although it is nice to have for the static
library.

Therefore, on a build as shared library, CMake will set the
-DEP1CBTSHARED compiler flag which causes the
-DDISABLEEP1CBTEXPORTEXCEPTIONS and -DDISABLEEP1CBTEXPORTCLASSES flags
to be ignored. In addition, CMake will set the visibility properties
independently from the parent project.

As a result, the flags work as advertised on a static build and the
result of the dynamic build will always be a usable libcanbustoolbox.so.