Remove obsolete GeoModelCppHelpers package and clean code
This MR removes the now obsolete GeoModelCppHelpers
package: all its methods have been moved to the global helper package GeoModelCore/GeoModelHelpers
.
This "fixes" the issue with the CMake include configuration spotted by @akraszna in !333 (closed) by completely removing the offending package.
The MR also fix one of the GeoStrUtils
helpers by adding a missing template type (Cc: @jojungge)
Edited by Riccardo Maria Bianchi