Add a property to set the default month view in the DatePicker when no value is selected

[Behfar90]

Currently, the datepicker always defaults to displaying the current month with today's date highlighted when no value has been selected. While this behavior works for many use cases, it would be beneficial to have a property that allows developers to control the initial month displayed when the picker is opened and no date value is pre-filled.

For example:

If today's date is December 19, clicking the picker shows December by default.
A new property (e.g., defaultMonth) could enable the picker to open on a different month, such as January or any other specified month, improving flexibility for applications where the current month isn't the most relevant.
This feature would enhance usability for scenarios where users are more likely to select dates outside the current month, streamlining their interaction with the component.

Thank you for considering this enhancement!