Recover from panics caused by goja

[2hamed]

Making sure k6 never panics (#1601 and #1487) by adding defer..recover blocks. I'm not sure about the performance penalty though.

[CLAassistant]

All committers have signed the CLA.

[na--]

Thanks for making this PR and sorry for the late review!

Unfortunately the current change you propose doesn't encompass all executors. Looking at the code, it might be better to have a single recover() block in the lambda returned by the getIterationRunner() helper function, which is used in all executors: https://github.com/loadimpact/k6/blob/c22338c57edc61d808c5d0ec4f3b6f2c3b68fcfb/lib/executor/helpers.go#L82

Also, I don't see a reason for changing the import order?

Edit: also, could you please rebase on the latest master, we've switched our CI system to GitHub Actions now.

[mstoykov]

Thanks for the PR @2hamed , but I wanted to actually get this in v0.29.0 and add some goja stack trace so I did this in #1697, and now that this is merged I need to close this PR, sorry :(.