Implement logging

[AlexDo1]

Some kind of logging is needed, similar to the logging in json2args if though this will be a little bit more tricky in R.

[Ash-Manoj]

@mmaelicke @AlexDo1
While implementing the tool_catflow, I encountered the same requirement. Do we have a fix for this?

[mmaelicke]

@AlexDo1 if I build in the logging in the same way like in the Python package, would you be willing to update the package on CRAN?

[AlexDo1]

I can try to update the package on CRAN, I never did this and I guess that updating on CRAN is a bigger effort than on pip.
So once @mmaelicke implemented logging and @Ash-Manoj tested it with his tool I can do the update.

At the moment, I always get the latest version of json2aRgs from GitHub, so that would be the way for @Ash-Manoj to test it.