22.0-bugfix-PixelDigitization

This should solve the immediate problem reported in ATLASSIM-5333, an FPE due to divide-by-zero. (A small cleanup of cppcheck warnings was also performed). However, this deserves a deeper look from the experts in the algorithm to discover why the lookup of values from conditions so often results in the last value being returned. A Jira ticket will be created for this.