hardhat unittest stub

[defistar]

Change List:

• added template for hardhat unit test stub
• added commands linked to invoke new template function

[tintinweb]

awesome, thanks @defistar 🙌 I'll merge this into the upcoming v1.0x branch and turn it into an option instead of having multiple codelenses.

fixes #70

[defistar]

thanks @tintinweb