fix: add FormData to URLSearchParams constructor

Author: keithamus

Diff for: baselines/dom.generated.d.ts

@@ -15972,7 +15972,7 @@ interface URLSearchParams {
 
 declare var URLSearchParams: {
     prototype: URLSearchParams;
-    new(init?: string[][] | Record<string, string> | string | URLSearchParams): URLSearchParams;
+    new(init?: string[][] | Record<string, string> | string | URLSearchParams | FormData): URLSearchParams;
     toString(): string;
 };