Add setters for the failure and starvation reporters in IOApp

[BalmungSan]

As promised in Discord.
c.c. @armanbilge @djspiewak

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I will fix tests if we decide to move forward with this approach.
For now, I am more interested in gathering feedback about the proposal.

[BalmungSan]

IORuntime.createEventLoop does not receive a reportFailure argument.
Thus, I guess native either doesn't have this problem or the reporting functionality has not been implemented yet. I am assuming the latter, thus I decide to leave this ready to be called once that functionality is implemented.

[fredfp]

As reporter of #3993 I'm wondering if the starvation reporter is anything special here.

Errors are usually reported by printing to sdterr (e.g., cats.effect.IOApp.onNonMainThreadDetected), I was wondering if we should allow overriding the part that logs to the console/stderr (i.e., for redirection to a logger).

It is in that sense that I'm asking if starvation reporter is anything special, would it make sense to rather add (and allow overriding) something like def reportError(error: String): IO[Unit] and call this to report starvation, non main thread detected and other issues?