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/models/FormulaField.ts

@@ -0,0 +1,31 @@
+import { FormulaOutputType } from '../enums/FormulaOutputType';
+import { Field } from './Field';
+import { type ListValue } from './ListValue';
+
+export class FormulaField extends Field {
+  public outputType: FormulaOutputType;
+  public values: ListValue[];
+
+  constructor(
+    id: number,
+    appId: number,
+    name: string,
+    type: string,
+    status: string,
+    isRequired: boolean,
+    isUnique: boolean,
+    outputType: string,
+    values: ListValue[]
+  ) {
+    super(id, appId, name, type, status, isRequired, isUnique);
+
+    if (FormulaOutputType[outputType] === undefined) {
+      throw new Error(
+        `The outputType ${outputType} is not a valid FormulaOutputType.`
+      );
+    }
+
+    this.outputType = FormulaOutputType[outputType];
+    this.values = values;
+  }
+}