nodeinout-796921: Update Highlighter for NodeJS

This updates the NodeJS stub for the Highlighter in a similar way to
how the previous commit did for Firefox.

Signed-off-by: Joe Walker <jwalker@mozilla.com>
nodeinout-796921: Update tests for nodelist updates

3 tests failed to setup the document properly, and we added some
armouring to check for blank highlighters in the onLeave functions in
node and novelist types.

Signed-off-by: Joe Walker <jwalker@mozilla.com>
refactor-864370: Include stack in error output

Signed-off-by: Joe Walker <jwalker@mozilla.com>