Use a complete console implementation

Using `console-compat` package to get a console class that works across all node versions to implement a console inside the test workers that formats the logs before sending to the master process. This way:

1. We get more readable output
2. No more running out of memory
3. Get console.trace time and all things in node's console
Looking at the impl of console-compat (which I know you just copied from node source), it doesn't seem to pass this info along :(

Maybe to keep things simple, in TestRunner.js we could just wrap the two instance methods to append a `'ERR:'`/`'WRN:'` string token at the start of the string -- the rip that off here to distinguish between the two.

Hacky indeed, but it keeps the hackery localized and simple