Use a map of colours rather than big if statement to get the layer color
Use a map of colours rather than big if statement to get the layer color

The entire if-else tree turned out to be quite slow. Using a dict is a
lot faster.

Contributes to CURA-708

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