[Feature] The reporter ignores error causes (and possibly aggregate errors too)

[pygy]

The reporter should properly display error with causes and aggregate errors.

[dead-claudia]

Worth noting that aggregate errors are commonly used for error causes since the latter isn't broadly available yet. So you really should support both if you're going to support error causes.

[pygy]

This stems from a persona itch with error causes, actually, but the solution to both cases will look similar so I'll tackle them both.