Add --silent flag to gleam run and gleam build

[PastMoments]

This is especially useful for piping program's stdout to other things.

Brief discussion about it here: https://discord.com/channels/768594524158427167/1139046296439758858

[lpil]

Good suggestion, thank you. I think I would like to use a more verbose flag as --silent is is more likely to be something the Gleam program would want to use. Perhaps --no-print-progress?

This would be implemented by passing in the null telemetry instead of the one that prints to the console.

[inoas]

Would this be only about the stdout infos or also about warnings?

[lpil]

Only the progress information, warnings and errors would still be printed.

[ohamill]

I'd like to work this ticket, if possible. Should I proceed with naming the flag --no-print-progress?

[lpil]

Yes please 🙏

[erikareads]

I would love this!

[codereport]

Not sure if the --silent would suppress warnings as well but that would be very helpful.

[lpil]

It would not, no.

[inoas]

--warnings-as-errors would also be helpful for CI purposes (modifying the posix exit code to be 0) I am personally agains --no-warnings