Use new eslint-plugin-functional instead of tslint-immutable

src/tests/utility.ts

@@ -1,5 +1,5 @@
 export class Utility {
-    // tslint:disable-next-line:no-any
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
     public static jsonify(obj: object): any {
         const stringifiedJson = JSON.stringify(obj);
         return JSON.parse(stringifiedJson);