Changes for aucore-blockvote-15: AU Core Immunization

[dbojicic]

This PR addresses issues from the AU Core R1 Ballot for Comment aucore-blockvote-15: https://confluence.hl7.org/display/HAFWG/aucore-blockvote-15 AND https://jira.hl7.org/browse/FHIR-45968.

• Made the following changes to the AU Core Immunization:
  • removed Must Support from Immunization.protocolApplied, Immunization.protocolApplied.series, Immunization.protocolApplied.targetDisease, Immunization.protocolApplied.doseNumber[x] FHIR-44674, FHIR-44656, FHIR-44654
  • removed Must Support from Immunization.reasonCode FHIR-44654, FHIR-45968
• Updated 1 example to remove elements that are no longer Must Support
• Updated change log
• Updated general-requirements
• Updated terminology page to remove resources associated with elements that are no longer Must Support