referenceRange high and low not loading correctly

[hsolbrig]

loadfacts --conf db_conf -u 117 --sourcesystem "FHIR R4" -l -t json --dupcheck -rm -i http://build.fhir.org/observation-example-f001-glucose.json

Does not create the correct modifier codes. Instead of:

concept_cd	modifier_cd
FHIR:Observation.referenceRange	FHIR:Quantity.value
	FHIR:Quantity.code
	...

We need:

concept_cd	modifier_cd
FHIR:Observation.referenceRange	FHIR:Observation.referenceRange.low.value
	FHIR:Observation.referenceRange.low.code
	...

(Exact details of the code still needs to be established but..)