Add an event that fires when a user manually selected a date

[goremykin]

Please describe the feature you would like to request.

I would like to add a new event (selected), that will let you know when a user selected the date manually

What is the use-case or motivation for this proposal?

On my project, I have to do some actions after the user has selected the date manually. The event (change) does not suit me, because it is triggered when the date is changed programmatically. It is also triggered during calendar initialization

Is there anything else I should know?

I can implement this functionality and create a PR