Need implementation of SiPM photon counter smearing

[veprbl]

Is your feature request related to a problem? Please describe.
Current implementation of energy-dependent smearing parametrization

EICrecon/src/algorithms/calorimetry/CalorimeterHitDigi.cc

Lines 145 to 148 in 8050426

	? m_normDist(generator) * std::sqrt(
	std::pow(u_eRes[0] / std::sqrt(eDep), 2) +
	std::pow(u_eRes[1], 2) +
	std::pow(u_eRes[2] / (eDep), 2)

requires tuning, and procedures for that are not obvious. Smearing models grounded in our understanding of the hardware can be implemented instead.

Describe the solution you'd like
We would like to get an explicit signal smearing behavior expected for MPPC's, e.g. using formalizm described in reference
https://arxiv.org/pdf/1510.01102.pdf
This should account for low photon statistics and saturation effects.

Describe alternatives you've considered
Do sophisticated studies outside of the reconstruction framework, and tune tune resolution parameters to reproduce their results.

Additional context

[ruse-traveler]

Comment for posterity: I've added a flag indicating that this is pertinent to identified TDR wants from the calorimetry side. Namely, this might be relevant for developing HGROC-specific digitization models, which multiple subsystems expressed a desire for...