Add a new property to ISvg ApplyFixedColorToRootOnly

[pyscripter]

Rational

With the FixedColor set you paint all elements with that color. But there are use cases in which you have some elements inheriting color from Root and others that specify their fill color and you only want to adjust the elements that inherit color from root. See for example.

Notice how the outside shape adjusts its color but the colored elements do not.

This property will allow to style ajdust svgs with more than one color when the root color is the base and the elements that do not inherit that color stay as they are.

[pyscripter]

I have provided a PR that partially implements this issue. Partially since:

• It has not been implemented in the Cairo factory @luebbe
• There is no property support in TSvgIconItem or designer support @carloBarazzetta

This property can now be applied only by accessing the SVG of SVGIconItems and setting it via the interface.

This property is meant to be set on an icon by icon basis.