fix(alerts): Metric alert rule save error msg when missing rule name

[taylangocmen]

This restores the control state to alert rule name in the metric alert rule editor. Updates the error message with the missing fields. Also removes the ms from the Cumulative Layout Shift error trigger thresholds.

V3 metric example:

non-V3 metric example:

Error messages:

[dashed]

@taylangocmen Using the measurementType() function might be better as we add more non-duration based measurements to alerts in the future (e.g. Mobile Vitals):

sentry/static/app/utils/discover/fields.tsx

Lines 793 to 798 in e0fe30d

	export function measurementType(field: string): MeasurementType {
	if (MEASUREMENTS.hasOwnProperty(field)) {
	return MEASUREMENTS[field];
	}
	return 'number';
	}

Suggested change

	if (aggregate.includes('measurements.cls')) {
	if (measurementType(aggregate) !== 'duration') {

[taylangocmen]

Just measurementType(aggregate) would ignore the non-vital type aggregates like transaction.duration, so a combination of the two is needed

[dashed]

@taylangocmen Ah. In that case, aggregateFunctionOutputType() might be an option.

[taylangocmen]

Actually measurementType(aggregate) wouldn't work on alert MEASUREMENTS fields because the alert aggregate includes the aggregate function ie. percentile(measurements.lcp,0.5)' or p99(measurements.lcp) vs just measurements.lcp substring matching on every aggregate here isn't worth it.