Regression: StyledText reintroduces artifact line while rendering

[amartya4256]

Description
StyledText reintroduces the artifact lines in the editor at 175% after merging Rectangle.OfFloat.
The DPIUtil's scaleUp and scaleBounds method were unified for precision scaling and hence the previous implementation for the scaling is not valid anymore for styledText and the consumer must be adapted.

Reproduction
Steps to reproduce the behavior:

1. Switch to 175% monitor zoom.
2. Open an empty java class file.
3. The artifact lines are visible.

Expected Behavior
No artifact ines should be visible on the editor.

Note: The behaviour is introduced by eclipse-platform/eclipse.platform.swt#2269

[amartya4256]

New development: problem adjusting consumers (LineNumberRulerColumn) as there's a drift in the calculated values because of the floating points accumulating over loop for higher value numbers since we can only be precise till 6 floating point digits.

[amartya4256]

Should we bring back the old scaleUp and scaleBounds and only use scaleUp and scaleBounds for OfFloat when the supplied argument is of type OfFloat? We probably need to start adapting OfFloats for getBounds, getSize and so on for controls tho. Later on when we have these complete painting of everything and not over a loop (Like GEF), then we can get rid of the scaleUp and scaleBounds.

[amartya4256]

eclipse-platform/eclipse.platform.swt#2294 - These rough changes partially fix the problem. The skipped pixels in the styledTexts are fixed with this but that misaligns the LineNumberRulerColumnn from the styledText and needs to be adapted too, which doesn't seem straight forward because of the drift I mentioned earlier. I created another draft to show what I tried to fix the LineNumberRulerColumn. eclipse-platform/eclipse.platform.ui#3099

[amartya4256]

Here's the PR (idea) to reintroduce the DPIUtil's old scaling methods while keeping the neew one equally functional: eclipse-platform/eclipse.platform.swt#2295