Use floating geometry throughout

With fractional scaling integer based logical geometry may not match device pixels. Once we have a floating point base we can fix that. This also is important for our X11 scale override, with a scale of 2 we could get logical sizes with halves.

We already have all input being floating point, this doubles down on it for all remaining geometry.

• Outputs remain integer to ensure that any screen on the right remains aligned.
• Placement also remains integer based for now.
• Repainting is untouched as we always expand outwards (QRectF::toAdjustedRect().
• Decoration is untouched for now
• Struts are rounded to integers
• Rules are integer in the config, but floating in the adjusting/API This should also be fine.

At some point we'll add a method to snap to the device pixel grid. Effectively round(value * dpr) / dpr though right now things mostly work.

This also gets rid of a lot of hacks for QRect right and bottom which are very confusing.

Parts to watch out in the port are: QRectF::contains now includes edges QRectF::right and bottom are now sane so previous hacks have to be removed QRectF(QPoint, QPoint) behaves differently for the same reason QRectF::center too

In test results some adjusted values which are the result of QRect.center because using QRectF's center should behave the same to the user.