Merge pull request #2924 from CyrusBiotechnology/for_commons/indigo/nmer_refactor
NMerSVMEnergy core::Size underrun bug (from Cyrus)
Fixes the addsan and numerical instability bugs in NMerSVMEnergy exposed by its new test.
shoutouts to @indigogo and @vmullig for commentary and assistance
shoutouts to @roccomoretti and @jaumebonet for notification.