Inconsistent licenses install location

Various VTK module licenses are installed to /usr/share/licenses/VTK/, but the main VTK license is installed into /usr/share/doc/VTK. Also, module licenses install into "VTK" via CMAKE_PROJECT_NAME:

    set(_vtk_build_LICENSE_DESTINATION "${CMAKE_INSTALL_DATAROOTDIR}/licenses/${CMAKE_PROJECT_NAME}")

but on Fedora the vtk rpm is named "vtk" and so the files would be better located in /usr/share/licenses/vtk. But I'm pretty sure we don't want to be messing with CMAKE_PROJECT_NAME.