Apply dd4hep single particle momentum patch to 1.18 as well

This will be fixed in anything after 1.18 since patch was included in dd4hep master as of Sept 20, 2021, but 1.18 was tagged earlier in Sept.

assigned to @sly2j

enabled an automatic merge when the pipeline for c82acc7f succeeds

changed title from Apply single particle momentum patch to 1.18 as well to Apply dd4hep single particle momentum patch to 1.18 as well

For future reference, github.com/AIDASoft/DD4hep commit 535efcab734639d3c8232ceb32f596fc1ae3fa29 contains the new approach we will want to transition to (the patch won't apply anyway to versions beyond 1.18).

merged