SLD: use propertyname for attribute binding

[assefa]

In some cases, the SLD property name attribute can be used for attribute binding. We currently have binding on the property name part of the rotation property used as a binding for text rules. We should support other elements to also have the possibility to use property binding.

[assefa]

MapServer allows binding on:

enum MS_STYLE_BINDING_ENUM { MS_STYLE_BINDING_SIZE, MS_STYLE_BINDING_WIDTH, MS_STYLE_BINDING_ANGLE, MS_STYLE_BINDING_COLOR, MS_STYLE_BINDING_OUTLINECOLOR, MS_STYLE_BINDING_SYMBOL, MS_STYLE_BINDING_OUTLINEWIDTH, MS_STYLE_BINDING_OPACITY};

enum MS_LABEL_BINDING_ENUM { MS_LABEL_BINDING_SIZE, MS_LABEL_BINDING_ANGLE, MS_LABEL_BINDING_COLOR, MS_LABEL_BINDING_OUTLINECOLOR, MS_LABEL_BINDING_FONT, MS_LABEL_BINDING_PRIORITY};

These could be used to different parts of the SLD symbolisers. TODO: Need to go through them and find all elements that make sense to bound.

Note that we have rotation bound for text symboliser

Another obvious one asked on the list is rotation of Grpahics. This is committed in 10666.

Should also update doc at the end of this.