chore: remove isNaN util, re-organize validate utils (#8473)

src/datetime-picker/utils.ts

@@ -1,5 +1,4 @@
 import { PropType } from 'vue';
-import { isNaN } from '../utils/validate/number';
 import { pickerProps } from '../picker/Picker';
 
 export type ColumnType = 'year' | 'month' | 'day' | 'hour' | 'minute';
@@ -42,7 +41,7 @@ export function getTrueValue(value: string | undefined): number {
     return 0;
   }
 
-  while (isNaN(parseInt(value, 10))) {
+  while (Number.isNaN(parseInt(value, 10))) {
     if (value.length > 1) {
       value = value.slice(1);
     } else {