fix: update error messages

Author: KhafraDev

lib/fetch/formdata.js

@@ -231,13 +231,13 @@ class FormData {
 
     if (arguments.length < 1) {
       throw new TypeError(
-        `Failed to execute 'forEach' on 'Headers': 1 argument required, but only ${arguments.length} present.`
+        `Failed to execute 'forEach' on 'FormData': 1 argument required, but only ${arguments.length} present.`
       )
     }
 
     if (typeof callbackFn !== 'function') {
       throw new TypeError(
-        "Failed to execute 'forEach' on 'Headers': parameter 1 is not of type 'Function'."
+        "Failed to execute 'forEach' on 'FormData': parameter 1 is not of type 'Function'."
       )
     }