[APM] Add support for very high durations (minutes and hours)

[sorenlouv]

Currently durations are formatted as either microseconds, milliseconds or seconds. We should add minutes and hours to support very slow transactions

kibana/x-pack/legacy/plugins/apm/public/utils/formatters.ts

Lines 81 to 91 in 91e1d9c

	export const getTimeFormatter: TimeFormatter = memoize((max: number) => {
	const unit = timeUnit(max);
	switch (unit) {
	case 's':
	return asSeconds;
	case 'ms':
	return asMillis;
	case 'us':
	return asMicros;
	}
	});

[elasticmachine]

Pinging @elastic/apm-ui