This utility function adds the union of any two or more cohort ids to the cohort definition set with a new id and name.
If a name parameter is not provided this will be auto generated as the union of the provided cohort id
addUnionCohortDefinition(
cohortDefinitionSet,
cohortIds,
cohortName,
unionCohortId
)cohort definition set
A vector of `cohort_definition_id` values for the input cohorts.
The Name of the resulting cohort
The `cohort_definition_id` for the resulting union cohort.