Fix contentFormatter for FormData returning an empty FormData object

Author: JorensM

templates/base/http-clients/fetch-http-client.ejs

@@ -104,9 +104,9 @@ export class HttpClient<SecurityDataType = unknown> {
     private contentFormatters: Record<ContentType, (input: any) => any> = {
         [ContentType.Json]: (input:any) => input !== null && (typeof input === "object" || typeof input === "string") ? JSON.stringify(input) : input,
         [ContentType.Text]: (input:any) => input !== null && typeof input !== "string" ? JSON.stringify(input) : input,
-        [ContentType.FormData]: (input: any) =>
-            Object.keys(input || {}).reduce((formData, key) => {
-                const property = input[key];
+        [ContentType.FormData]: (input: FormData) =>
+            (Array.from(input.keys()) || []).reduce((formData, key) => {
+                const property = input.get(key);
                 formData.append(
                     key,
                     property instanceof Blob ?