External Answer Value Set Resolver
interface ExternalAnswerValueSetResolver
Resolves external answer value sets not defined in the questionnaire's contained
element. This allows the library to render answer options to choice
and open-choice
type questions more dynamically.
NOTE: The result of the resolution may be cached to improve performance. In other words, the resolver may be called only once after which the same answer value set may be used multiple times in the UI to populate answer options.