Findgl2ps.cmake, master branch (2023.01.24.)
Added Findgl2ps.cmake
for setting up this external from an LCG release. Which, as discussed in ATLINFR-4819, became necessary with new LCG / ROOT versions.
As written in the code, based the "version extraction" on: https://github.com/Kitware/VTK/blob/master/CMake/FindGL2PS.cmake