Support Units Of Measure codes

[lp]

add support for http://unitsofmeasure.org

[biximilien]

@lp UCUM codes are built into HAPI FHIR conformance resources we do not need to ingest these codes - the list is technically infinite and HAPI already knows how to lookup the UCUM codes:

GET http://localhost:8080/fhir/CodeSystem/$lookup?system=http://unitsofmeasure.org&code=ng/L

{
  "resourceType": "Parameters",
  "parameter": [ {
    "name": "display",
    "valueString": "(nanogram) / (liter)"
  }, {
    "name": "abstract",
    "valueBoolean": false
  } ]
}

I believe we can close this issue