[Bug-4023] : Incorrect placeholder in the datepicker widget

-- Change date format to `YYYY-MM-DD HH:mm`

app/client/src/components/designSystems/appsmith/TableComponent/CascadeFields.tsx

@@ -568,7 +568,7 @@ const Fields = (props: CascadeFieldProps & { state: CascadeFieldState }) => {
         <DatePickerWrapper className="t--table-filter-date-input">
           <DatePickerComponent
             label=""
-            dateFormat="DD/MM/YYYY"
+            dateFormat="YYYY-MM-DD HH:mm"
             datePickerType="DATE_PICKER"
             onDateSelected={onDateSelected}
             selectedDate={value}

app/client/src/components/propertyControls/DatePickerControl.tsx

@@ -82,7 +82,7 @@ class DatePickerControl extends BaseControl<
           parseDate={this.parseDate}
           maxDate={this.maxDate}
           minDate={this.minDate}
-          placeholder="DD/MM/YYYY HH:mm"
+          placeholder="YYYY-MM-DD HH:mm"
           timePrecision={TimePrecision.MINUTE}
           closeOnSelection={true}
           onChange={this.onDateSelected}

app/client/src/mockResponses/WidgetConfigResponse.tsx

@@ -111,10 +111,10 @@ const WidgetConfigResponse: WidgetConfigReducerState = {
       datePickerType: "DATE_PICKER",
       rows: 1,
       label: "",
-      dateFormat: "DD/MM/YYYY HH:mm",
+      dateFormat: "YYYY-MM-DD HH:mm",
       columns: 5,
       widgetName: "DatePicker",
-      defaultDate: moment().format("DD/MM/YYYY HH:mm"),
+      defaultDate: moment().format("YYYY-MM-DD HH:mm"),
       version: 1,
     },
     DATE_PICKER_WIDGET2: {
@@ -122,7 +122,7 @@ const WidgetConfigResponse: WidgetConfigReducerState = {
       datePickerType: "DATE_PICKER",
       rows: 1,
       label: "",
-      dateFormat: "DD/MM/YYYY HH:mm",
+      dateFormat: "YYYY-MM-DD HH:mm",
       columns: 5,
       widgetName: "DatePicker",
       defaultDate: moment().toISOString(),