Allow pause heat/cool on ferment step#302

For each fermentation step, support pausing heating and/or cooling.

When pitching yeast, it’s desirable to pause cooling for 1st 24hours to prevent shock to yeast growth. When performing d-rest, cooling isn’t always needed (free rise) so would be good to turn cooling off. When crash cooling, no need for heater - even if crash cool temp is over shot.