misc(cli): improve error if invalid value for --output argument is passed

[svkrclg]

Summary
Improve --output error message for invalid values.

Related Issues/PRs
#12787

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[svkrclg]

@googlebot I signed it!

[adamraine]

nit

Suggested change

	} return true;
	}
	return true;

[svkrclg]

hey @adamraine how can I retrigger the failed checks?

[patrickhulce]

@svkrclg I restarted them for ya :)

[svkrclg]

Thanks @patrickhulce .
Also, are there existing issues with the failed checks? Mostly the errors are related PROTOCOL_TIMEOUT, Segmentation fault (core dumped)

[patrickhulce]

Yes we are currently struggling with many node and Chromium side bugs in our tests :/ don't worry about those definitely not your doing! we're trying to sort out those issues this week.

[svkrclg]

Great, thanks @patrickhulce