🩹(react) harmonize date picker components output

By introducing this utility function, we ensure that any output value
is converted back to an ISO 8601 date and time string in UTC timezone.
Overall, it harmonize and factorize the way we output
values from date picker components.

packages/react/src/components/Forms/DatePicker/utils.ts

@@ -1,7 +1,11 @@
 import {
   CalendarDate,
+  DateValue,
   parseAbsoluteToLocal,
   toCalendarDate,
+  ZonedDateTime,
+  toZoned,
+  getLocalTimeZone,
 } from "@internationalized/date";
 import { DateRange } from "react-aria";
 import {
@@ -38,6 +42,19 @@ export const parseRangeCalendarDate = (
   };
 };
 
+export const convertDateValueToString = (date: DateValue | null): string => {
+  try {
+    const localTimezone = getLocalTimeZone();
+    // If timezone is already set, it would be kept, else the selection is set at midnight
+    // on the local timezone, then converted to a UTC offset.
+    return date ? toZoned(date, localTimezone).toAbsoluteString() : "";
+  } catch (e) {
+    throw new Error(
+      "Invalid date format when converting date value on DatePicker component"
+    );
+  }
+};
+
 export const getDefaultPickerOptions = (props: DatePickerAuxSubProps): any => ({
   minValue: parseCalendarDate(props.minValue),
   maxValue: parseCalendarDate(props.maxValue),