fix: make sure that errors from before hook are reported

[jmcdo29]

I've added in a try/catch to catch any errors that happen in the before hook so that they can be reported on and properly have the exit code of 1. If you'd like me to update any of the code styles, let me know. Been loving this test runner so far.

Closes #191
Closes #201

[jmcdo29]

@lukeed sorry to be a bother with the ping, just wondering if we can get this looked at? I've loved using uvu so far and want to make it my defacto test runner, this is the missing piece for me at the moment (writing try/catch in the before is rather cumbersome to continually do)

[skibz]

Please review this for merge. It's a huge quality-of-life improvement to this library.

[randomer]

Just stumbled upon this bug. Is there any chance of it getting merged anytime soon?

PS: @lukeed Thanks for this library, it's easily the fastest JS test runner I've ever used!