Convert a native OCF stakeholder relationship string to DAML enum. Uses exact string matching (case-insensitive) with fallback to OTHER for unknown values.
Native relationship string (e.g., 'EMPLOYEE', 'BOARD_MEMBER')
DAML stakeholder relationship type enum value
Convert a native OCF stakeholder relationship string to DAML enum. Uses exact string matching (case-insensitive) with fallback to OTHER for unknown values.