refactor: remove tryCatch() that hides the error message

[maelle]

I noticed that the tryCatch() did not work because the error condition does not have access to service_url. Furthermore, what was needed for me was the actual error. So I propose removing check_service() and instead document the existence of the monitor.

Note the builds won't pass until #159 or another fix is merged.

[salvafern]

Hi @maelle , I believe we will be loosing some nice error messages as well (e.g. no internet). But surfacing other error messages is also a good idea. I agree but maybe would be good a quick review by @annakrystalli ?

[maelle]

I can see that but at the same time, if one doesn't have an internet connection, it's easy to notice even without R? 🤔

[salvafern]

fair enough :)