[DatePicker]: Enhance focus retention in input field.

## Now
Currently, when a user clicks on the date picker field or presses the Enter key, the focus immediately shifts to the body of the date picker.

https://github.com/user-attachments/assets/65775db1-6744-434d-9291-90c5cc214b95

## To Do
Modify the date picker behavior so that when a user clicks on the input field or presses Enter, the focus remains within the input field itself, similar to how it is managed in the range date picker.

https://github.com/user-attachments/assets/003fbab1-02e2-42d0-8a52-c77eddeb6e40