Add has_internet function to test_helpers

[taldcroft]

Description

Quick helper to determine if internet is available. Got this solution from https://stackoverflow.com/questions/3764291.

Testing

• [n/a] Passes unit tests on MacOS, linux, Windows (at least one required)
• Functional testing (MacOS and Windows)

Functional testing

Ran on local Mac and Windows and got expected True. Ran on cheru and got expected False.

[jeanconn]

LGTM. I assume socket plays nice on windows as well. In running testr tests, I don't know... do we more often need to know if the machine has internet or if the machine is on GRETA (and do we handle those about the same?)?

[taldcroft]

I just tested on Windows and it worked fine, good idea.

Fundamentally we want to know if the machine has internet. That could be me running tests while on a plane, who knows.