Respect keyboard layout

[haavamoa]

With the current solution of our sheet, the consumer has to modify the position of the sheet when a entry based control has focus. The consumer can set the Position=1 when a entry has focus. That way the sheet will get translated and moved so the keyboard has space.

This would be much better if it could be handled by the sheet it self.

[haavamoa]

Android:

• https://stackoverflow.com/questions/4745988/how-do-i-detect-if-software-keyboard-is-visible-on-android-device

• https://stackoverflow.com/questions/25216749/soft-keyboard-open-and-close-listener-in-an-activity-in-android

Android and ios:

• https://stackoverflow.com/questions/46360257/xamarin-forms-check-if-keyboard-is-open-or-not

[haavamoa]

This is fixed in our MAUI library, and we do not plan to fix this in the Xamarin version:

https://github.com/DIPSAS/DIPS.Mobile.UI