fix(file size): use Long instead of float

Float only stores up to 16 million, and file size is stored in bytes. A video can easily be over 16MB (16 million bytes), therefore Long is needed.

src/main/java/com/ddf/vodsystem/dto/ClipOptions.java

@@ -27,5 +27,5 @@ public class ClipOptions {
     private Integer height;
 
     @Positive
-    private Float fileSize;
+    private Long fileSize;
 }