Round autoscaling to make vertical divisions integer on grid

[planetchili]

Auto-migrated from intel-sandbox/applications.graphics.presentmonservice/issues/232

^{Original creation by planetchili on 2023-05-24 06:55:11+00:00}

Just make the size of divisions integral, like 3 or 17? or snap to larger quantizations, like 5, 10, 25, 50, 100?