Add tooltip for current bed temperature
Add tooltip for current bed temperature

Contributes to issue CURA-3161.

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