Support react-native-svg for RNW vNext

[namrog84]

https://github.com/react-native-community/react-native-svg

A lot of our app leverages stuff from react-native-svg and it's variety of views. For drawing gradients, vector graphics, on screen controls, and misc other things.

This has been a huge pain point for us trying to work around. As some of our buttons are deeply integrated with this, and we currently have no easy way of working around it.

[chrisglein]

Our first priority is to fix #3573. which should unblock primary scenarios and lower the immediate priority for adding support to this community module.

[adam-bratin]

There is still a pretty large use case that is not covered by #3573, which is trying to create animated components. There are quite a few libraries (e.g. react-native-circular-progress, react-native-progress) that require more than static svg support. Now some of this can be supported by the addition of lottie that I think is being tackled in another issue, but I would love to be able to use existing libraries dependent on either react-native-svg or @react-native-community/art

[chrisglein]

Our priority for animated vector graphics is to pursue lottie first via #3278. Both would be great, of course.