What

• Refactor mapCodeableConceptForMedication and mapCodeableConceptToCd to reduce code duplication.
• Refactor mapCodeableConceptToCdForAllergy for readability.
• Add a test case when mapping to null flavor codeable concept for allergy when a SNOMED code is not present.
• Remove unnecessary nesting in findOriginalTextForAllergy as the equals already handles case where it is not present.
• Remove check for resolved clinical status as call to method getOriginalTextForActiveAllergy yields as the fallback method contains the exact same functionality.
• Removed unnecessary isEmpty check as fallback was to return an Optional.empty() which so this is already implied.

Why

Improving code quality and readability, preparing for further work on NIAD-3304

Type of change

Please delete options that are not relevant.

• Internal change (non-breaking change with no effect on the functionality affecting end users)

Checklist:

• I have performed a self-review of my code
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes