Resolve animation issues with Date picker

[disc0infern0]

• Refactored date/time pickers to new view and updated control of state with new enum, allowing animations of picker view transitions to be handled precisely with new function setPickerState.
• No settings for transitions or animations work well (in a Form) when transitioning from a state where the date picker is shown, so use the setPickerState function to make transitions from a date picker shown state without animation, but animate all other view transitions.
• There is now no janky animation whatsoever, but 2 out of the 6 possible transitions now happen without animation.