Add countdown timer for pre-heat time
Add countdown timer for pre-heat time

Not happy with how there is '900' in multiple places in the code. I might do something about that later.

Contributes to issue CURA-3161.

hmflash/Cura,ynotstartups/Wanhao,Curahelper/Cura,hmflash/Cura,fieldOfView/Cura,Curahelper/Cura,fieldOfView/Cura,ynotstartups/Wanhao