v4.3.0: Coordinate conversion to scrolling text and animation position

• Adds the textCoordForFramePoint function, which converts a point in a MarqueeLabel's frame coordinate system to a point in the scrolling label's coordinate system. It could be useful for determining the word or character under a user tap point, as now demonstrated in the demo project here. (thanks to @LucaGaspa for the feature request!)
• Adds an animationPosition property that describes the position of the scroll animation (can be queried while the animation is in-progress). (thanks to @alexandre-odet for the suggestion!)