[results] increase object-inspect depth for expected/actual

[scottbessler]

It may be best for this to be configurable, but for now 5 seems like
a default that is often too low resulting in confusing output that shows
expected/actual to be identical when the difference is >5 deep.

[ljharb]

I think if we're going to make a change like this, we might as well allow it to be configurable.

Personally I think 5 is way way too deep to avoid confusion, let alone 10 - so clearly that number is subjective.

[scottbessler]

I hear ya. Made it configurable via opts.objectPrintDepth

[ljharb]

This seems reasonable to me, thanks (it'll be a semver-minor).

I'll leave this here for a few more days before merging.