Improved NotOnArtCalculation to stop loading patient observations individually so that it is more efficient. PT Story: https://www.pivotaltracker.com/story/show/64215706

(cherry picked from commit 2bbf4993f0d64c267a307051742900236c50b94f)

Conflicts:
	api/src/main/java/org/openmrs/module/kenyaemr/calculation/library/mchms/NotOnArtCalculation.java