Remove 'l' formatting character and simplify+speed-up int2mm formatting
Remove 'l' formatting character and simplify+speed-up int2mm formatting

The 'l' formatting character in combination with 'd' was not allowed with MinGW on Windows. Simply formatting with 'd' is sufficient since our coordinates are allowed to be cast to integers at this stage: We won't need to square them any more or anything.

Contributes to issue CURA-3274.

ROBO3D/CuraEngine,alephobjects/CuraEngine,Ultimaker/CuraEngine,alephobjects/CuraEngine,Ultimaker/CuraEngine,alephobjects/CuraEngine,ROBO3D/CuraEngine,ROBO3D/CuraEngine