WMS Extended capabilities and operations

[pomadchin]

WMS 1.3.0 allows to use ExtendedCapabilities field to expose some vendor parameters available for the requested source. The problem with it that it can be of an arbitrary format.

I could find some real examples of what it may look like:

Example1, Example2

This task is to expose Vertical Exaggeration and Scale Factor as parameters in MAML Hillshade and Slope directives through GetCapabilities.