Use Fluent Lottie Animation for Fabric ActivityIndicator

[TatianaKapos]

Summary

Fabric ActivityIndicator is currently a simple comp animation but we should use the more modern Lottie animation in the future. This is dependent on SVG and adopting FURN control but we can track the progress here.

Motivation

To make fabric RNW more modern

Basic Example

https://learn.microsoft.com/en-us/windows/winui/api/microsoft.ui.xaml.controls.progressring?view=winui-2.8

[chrisglein]

By using the same Lottie animation that's used by WinUI we will match whatever the current Fluent design standard is (which could change in the future). They use Lottie to code gen composition calls:
https://github.com/microsoft/microsoft-ui-xaml/blob/main/dev/ProgressRing/AnimatedVisuals/ProgressRingIndeterminate.h
Which (with some adaptation) should also be compatible with our composition-based version of RNW.