propagate execution errors up as notifications

[HotelCalifornia]

in purduesigbots/pros-atom3#38, we saw that click's error message relating to atom's locale setting was hidden in the debug console. had the error message been shown to the user, it's possible they would have been able to fix the issue themselves by following the instructions here.

I'm not really sure why that error didn't make it up as a notification, but it definitely should be one

[HotelCalifornia]

relevant lines here:

pros-cli-middleware/src/util.ts

Lines 16 to 20 in e303c36

	for (var line of raw.split(EOL)) {
	if(!line.startsWith(PREFIX)) {
	console.error(line);
	continue;
	}

this should probably be refactored so that we don't just spam every line as its own message, as seen here:

but I'm not really sure the best way to go about it. in theory, some error messages could appear in the middle of normal execution