DateTimePicker: Add button so its not just clicking outside of the control

[nicolajb23]

Feature Type
[ ] Clarity Port
[ x ] Enhancement

Description
Currently to complete editing the date & time you have to click outside of the popup.
Request is to add a button to confirm - maybe OK/Cancel buttons like material.io
https://material.io/components/time-pickers

[karan-kang]

Preview of new Implementation coming in v0.12.0

Clicking 'OK' will pass the values to the bound Input control.
Clicking 'Cancel' will revert the value back to what it was before the date time dropdown was opened.