🐛 Add missing datepicker close call onPopperKeyDown event - to handle ESC keydown event outside the day component

[balajis-qb]

Description

Linked issue: Hacker0x01#5520

Problem
As mentioned in the linked issue, the datepicker needs 2 esc key press to close. This is not happening always. If the control is there in any days, then one ESC key itself is closing the date picker. But if it's there in the DatePicker header (For E.g., Previous or Next month navigation button), then the first ESC key will just move the focus back to the DatePicker Input and then second Esc key only will close the DatePicker.

To Reproduce
Steps to reproduce the behavior:

1. Go to a page with react-datepicker rendered.
2. Click on the input field to open the calendar and click back and next navigate button for more than one times.
3. Press Escape.
4. Observe that the calendar remains open (It just moves the focus to the input).
5. Press Escape again.
6. Calendar finally closes.

Changes

• Added the missing handleClose call to the onPopperKeyDown event handler
  

Contribution checklist

• I have followed the contributing guidelines.
• I have added sufficient test coverage for my changes.
• I have formatted my code with Prettier and checked for linting issues with ESLint for code readability.