Use timestamp from Animation Backend in Animated (#55206)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/55206

To avoid timestamp representation bugs with different platforms passing the timestamp as a simple double, we now use `std::chrono::duration<double, std::milli>` to represent timestamps.

# Changelog
[General] [Added] - `AnimationTimestamp` to `UIManagerAnimationBackend`
[General] [Changed] - updated `AnimationBackend` usages to use `AnimationTimestamp`

Reviewed By: zeyap

Differential Revision: D90505538

fbshipit-source-id: 98761ac0060612e9ed9a57c9952656cae70c30f1