[TSVB] Add numeral support for duration fields

[shaharmor]

Kibana version: 6.0.0-rc1

Description of the problem including expected versus actual behavior:
When formatting a metric visualization as a duration (I.E from milliseconds to minutes), the number isn't formatted with numeral.js which makes it just a long number (Without commas).
Instead of having the decimal places option, we can replace it with a numeral.js format which will just run numeral(value).format(format) after the duration conversion here: https://github.com/elastic/kibana/blob/6.x/src/core_plugins/metrics/public/components/lib/tick_formatter.js#L37

Steps to reproduce:

1. Create a metric TSVB visualization
2. Change field formatter to duration
3. See number is not formatted with commas

[stratoula]

Duplicate of #153378