Better animation for button reshaping

[ghost]

When showing advanced functions in the normal view of the calculator, the buttons are immediately reshaped to fit into the new space before the animation for button movement plays out. This looks specially odd when hiding the advanced functions, since the buttons become larger and visibly overlap with one another before the buttons are moved to their new position.

It'd be better to animate the button reshaping alongside button movement similar to what Google's stock calculator does. A FOSS app which implements this type of behavior is Unitto when performing and operation and making extra space to show the result. Here is the comparison:

Unitto	OpenCalc
https://user-images.githubusercontent.com/86078431/218274454-1fc3effc-f5a9-4e34-972c-5139e1274b71.mp4	https://user-images.githubusercontent.com/86078431/218274458-b1178db3-a07e-43d1-9d4d-918c85cc75a6.mp4