--out-itf should not supress output

[bugarela]

We already have a --verbosity flag for that.

I personally almost always miss the output when running with --out-itf. My reasoning is: I would like to use the ITF trace for some machine task (i.e. rendering some graphic thing about the trace or using it in a MBT test), and for that, I'd like to know what happened in the trace to know if my machine task corresponds to my expectations. What I find myself doing is inspecting the ITF trace to see what happened in that particular execution, but I'd much rather inspect it in the Quint-formatted trace I'm used to reading.

If most people prefer --out-itf to produce no terminal output, we can make it so it changes the default verbosity to 0, and then we just have to set a higher verbosity to see the output.