Show `console.log` output in extension output panel or inline failure message

[mtharrison]

For debugging purposes, console.log statements within tests are not currently visible in the extension.

Current behaviour

Console output from tests is not captured or displayed anywhere accessible via the extension.

Suggested behaviour

Pipe console.log output to one or both of:

1. The extension's output panel
2. The inline failure message that appears in the editor

This would significantly improve the debugging experience when tests fail.

---

Feedback from Kevin Paxton