fix(url validation): correct URL validation for empty fields (#1657)

The isValidURL function was returning false when the provided value was undefined/null/empty, but
needs to return true instead so it doesn't interfere with Yup validation.

src/utils/urlValidationHelper.ts

@@ -1,7 +1,9 @@
 export function isValidURL(value: unknown) {
   try {
     let url: URL;
-    if (typeof value === 'string') {
+    if (value === undefined || value === null || value === '') {
+      return true;
+    } else if (typeof value === 'string') {
       url = new URL(value);
     } else if (value instanceof URL) {
       url = value;