Avoid overlays and messages on stderr that is unrelated to exception handling

[vemv]

Fixes #3587

[vemv]

@rrudakov kindly LMK if this would fix it

(from my experiments/analysis it would, but I never got to reproduce the Timbre error)

It would solve the overlays and messages alike, since the message is produced by the overlay function

Cheers - V

[vemv]

Mmm, I'll have to refine this approach, because it essentially relies on analyze-last-stacktrace.

There's no guarantee that the 'last stacktrace' is related to the 'most recent eval' - it could store an unrelated exception from prior evals.

This could be quite easily fixed by changing analyze-last-stacktrace -> (analyze-stacktrace err)

(So back to WIP - sorry for the noise @rrudakov)

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Edit: note to self - analyze-stacktrace didn't work.

Next best approach is parsing runtime exceptions, just like we do for compile-time ones.