Fixed #2057 - calendar component type null issue (#2053)

I m following this demo    [https://codesandbox.io/s/hejhs?file=/src/demo/CalendarDemo.tsx:2121-2154](url)   which contains some errors  in all    setDate hooks  like this one  setDate8(e.value) 

 here is the error description 

 CalendarChangeParams.value: Date | Date[] | null | undefined
Argument of type 'Date | Date[] | null | undefined' is not assignable to parameter of type 'SetStateAction<Date | Date[] | undefined>'.
  Type 'null' is not assignable to type 'SetStateAction<Date | Date[] | undefined>'.ts(2345)

when I check the declaration file of the calendar component I found that the interface CalendarChangeParams contains the value propriety which may have a null I tried to change this and I removed the null option it works fine so thank you,  for verifying this issue.

src/components/calendar/Calendar.d.ts

@@ -11,7 +11,7 @@ interface CalendarChangeTargetOptions {
 
 interface CalendarChangeParams {
     originalEvent: React.SyntheticEvent;
-    value: Date | Date[] | undefined | null;
+    value: Date | Date[] | undefined;
     stopPropagation(): void;
     preventDefault(): void;
     target: CalendarChangeTargetOptions;