[Reland] Introduce AnimationStyle (#138721)
This PR introduces `AnimationStyle`, it is used to override default
animation curves and durations in several widgets.
fixes [Add the ability to customize MaterialApp theme animation
duration](https://github.com/flutter/flutter/issues/78372)
fixes [Allow customization of showMenu transition animation curves and
duration](https://github.com/flutter/flutter/issues/135638)
fixes [`AnimationStyle.noAnimation` needs to replace `AnimatedTheme`
with just `Theme` in the
`MaterialApp`](https://github.com/flutter/flutter/issues/138618)
Here is an example where popup menu curve and transition duration is
overridden:
```dart
popUpAnimationStyle: AnimationStyle(
curve: Easing.emphasizedAccelerate,
duration: Durations.medium4,
),
```
Set `AnimationStyle.noAnimation` to disable animation.
```dart
return MaterialApp(
themeAnimationStyle: AnimationStyle.noAnimation,
```
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- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
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