merge changes which adds convenience methods for calculating the fitted waveform
merge changes which adds convenience methods for calculating the fitted waveform

openxal/openxal,openxal/openxal,EuropeanSpallationSource/openxal,openxal/openxal,openxal/openxal,luxiaohan/openxal-csns-luxh,EuropeanSpallationSource/openxal,luxiaohan/openxal-csns-luxh,luxiaohan/openxal-csns-luxh,EuropeanSpallationSource/openxal,luxiaohan/openxal-csns-luxh,EuropeanSpallationSource/openxal,openxal/openxal,EuropeanSpallationSource/openxal