Correct markup of Observation.component.code, etc.

Existing Wording:

For Multiplex Assay tests that serve as a single test to diagnose infection caused by multiple viruses (e.g. CDC Flu SC2 Multiplex Assay for SARS-CoV-2, influenza A, and/or influenza B viruses): ** Observation.component.code - value set containing the use case specific test types ** Observation.component.value - value set containing the use case specific test results

(Comment 36 - imported by: Ron G. Parker)