Shoaib Mushtaq

Add variable Extension support

15

**IMPORTANT: All PRs must be linked to an issue (except for extremely trivial and straightforward changes).** Fixes #1059 **Description** The implemented approach is, 1. Made a child-to-parent map for `QuestionnaireItems`...

R4 FHIRPathEngine resolveConstant of EvaluationContext doesn't support returning multiple values

2

In the context of a [conversation](https://chat.fhir.org/#narrow/stream/179266-fhirpath/topic/variables/near/290859425) with @grahamegrieve over zulip chat, R4 FHIRPathEngine [public Base resolveConstant(Object appContext, String name, boolean beforeContext) method](https://github.com/hapifhir/org.hl7.fhir.core/blob/master/org.hl7.fhir.r4/src/main/java/org/hl7/fhir/r4/utils/FHIRPathEngine.java#L202) of EvaluationContext Interface doesn't support returning multiple values....

**IMPORTANT: All PRs must be linked to an issue (except for extremely trivial and straightforward changes).** Fixes #608 **Description** Clear and concise code change description. **Alternative(s) considered** Have you considered...