Request to provide full IGT debug logging for successful tests

This might require an IGT and an i915-infra component, since we don't necessarily want to print this information for all tests run locally by developers. But from a CI perspective, IMO, this is critical when tracking down issues resulting in warnings or otherwise failing only intermittently. Basically I want to be able to compare failure cases to successful cases.

It might also be interesting to see the general flow of successful cases for patches submitted to mail lists, at least for ones that include changes to IGT or which expect specific test interaction.