Date-/time picker

We should have a date-/time picker control that application developers can just drop into their UIs.

It should have the same look and feel as the platform as possible (if there is a standard control)

There are several approaches to this.

Proposal:

Have a date(time) input that just displays the date. This would similar to how the HTML (see links below) date input is rendered. The application developer just instantiates e.g. one single DateTimeEdit control that have time/date properties that will change when the user alters it. Depending on the platform, the date can be altered by:

1. Showing a popup with date (calendar) control where the user can choose the date
2. User can directly write the date into the date input with keyboard
3. Both

This way, the pickers are just an implementation detail, so it will be easy to have different editors depending on style/platform.

Editing the date should be possible with no extra glue/setup. We can also choose to expose the calendar/time pickers, and allow the developer to override how the editor is brought up.

Should we investigate if it is possible (and beneficial) to use native date/time pickers?

HTML: https://www.w3schools.com/html/tryit.asp?filename=tryhtml_input_date

Android: https://developer.android.com/reference/android/widget/TimePicker

iOS: https://developer.apple.com/documentation/uikit/uidatepicker?language=objc