feat: optimize type (#366)

Author: kiner-tang

src/IDialogPropTypes.tsx

@@ -1,13 +1,12 @@
 import type { GetContainer } from 'rc-util/lib/PortalWrapper';
 import type { CSSProperties, ReactNode, SyntheticEvent } from 'react';
 
-
 export interface ModalClassNames {
-  header: string;
-  body: string;
-  footer: string;
-  mask: string;
-  wrapper: string;
+  header?: string;
+  body?: string;
+  footer?: string;
+  mask?: string;
+  wrapper?: string;
 }
 
 export type IDialogPropTypes = {