fix: implement formula field, list field, and reference field as chilrden of the field class. fix: when converting api response data to appropriate field response make sure json field objects are converted to correct field class based upon type.

src/enums/FieldType.ts

@@ -68,6 +68,11 @@ export enum FieldType {
    */
   SurveyUnifiedAnswer = 'SurveyUnifiedAnswer',
 
+  /**
+   * @constant SurveyDelegation - The field is a survey delegation field.
+   */
+  SurveyDelegation = 'SurveyDelegation',
+
   /**
    * @constant Attachment - The field is a attachment field.
    * @type {string}