fix: moment ts error

Author: tangjinzhou

components/calendar/Header.tsx

@@ -4,6 +4,7 @@ import { Group, Button } from '../radio';
 import PropTypes from '../_util/vue-types';
 import { defaultConfigProvider } from '../config-provider';
 import { VueNode } from '../_util/type';
+import moment from 'moment';
 
 function getMonthsLocale(value: moment.Moment): string[] {
   const current = value.clone();

components/date-picker/props.ts

@@ -1,4 +1,5 @@
 import { PropType } from 'vue';
+import moment from 'moment';
 import PropTypes, { withUndefined } from '../_util/vue-types';
 import { tuple } from '../_util/type';
 

components/date-picker/utils.ts

@@ -1,3 +1,5 @@
+import moment from 'moment';
+
 type Value = moment.Moment | undefined | null;
 type Format = string | string[] | undefined | ((val?: Value) => string | string[] | undefined);
 export function formatDate(value: Value, format: Format) {