Remove "discharge" from MedicationRequest.category

[p9g]

References:
[1] https://jira.hl7.org/browse/FHIR-25555
[2] http://build.fhir.org/valueset-medicationrequest-admin-location.html
[3] http://build.fhir.org/valueset-medicationrequest-category.html
[4] http://build.fhir.org/medicationrequest-definitions.html#MedicationRequest.category
[5] http://hl7.org/fhir/us/qicore/STU4/qdm-to-qicore.html#8173-medication-discharge

The code "discharge" should not be used as discussed in [1].
Remove that code from MATGlobalCommon.
Update measures that check for MedicationRequest.category ~ "discharge"; only check for MedicationRequest.category ~ "community"

QDM to QI-Core mapping [5] correctly specifies Constrain category to “Community” (even though QDM "Medication, Discharge" has no setting attribute), consistent with [1].

e.g.,

draft-measures/bundles/release/fhir4/EXM104_FHIR4-8.1.000/EXM104_FHIR4-8.1.000-files/EXM104_FHIR4-8.1.000.cql

Line 84 in 06a7a43

where exists (Antithrombotic.category C where FHIRHelpers.ToConcept(C) ~ Global."Community" or FHIRHelpers.ToConcept(C) ~ Global."Discharge")

Latest definition [4] points to [2] instead of [3]; [2] does not have discharge.