Derive FromReflect for Transform and GlobalTransform (#6015)

# Objective

Both components already derives `Reflect` and it would be nice to have `FromReflect` in order to ser/de between those types without relaying on `downcast`, since it can fail between different platforms, like WebAssembly.

## Solution

Derive `FromReflect` for `Transform` and `GlobalTransform`.

I thought if I should also derive `FromReflect` for `GlobalTransform`, since it's a computed component, but there may be some use cases where a `GlobalTransform` is needed to be sent over the wire, so I decided to do it.

crates/bevy_transform/src/components/global_transform.rs

@@ -3,7 +3,7 @@ use std::ops::Mul;
 use super::Transform;
 use bevy_ecs::{component::Component, reflect::ReflectComponent};
 use bevy_math::{Affine3A, Mat4, Quat, Vec3, Vec3A};
-use bevy_reflect::Reflect;
+use bevy_reflect::{FromReflect, Reflect};
 
 /// Describe the position of an entity relative to the reference frame.
 ///
@@ -31,7 +31,7 @@ use bevy_reflect::Reflect;
 /// - [`global_vs_local_translation`]
 ///
 /// [`global_vs_local_translation`]: https://github.com/bevyengine/bevy/blob/latest/examples/transforms/global_vs_local_translation.rs
-#[derive(Component, Debug, PartialEq, Clone, Copy, Reflect)]
+#[derive(Component, Debug, PartialEq, Clone, Copy, Reflect, FromReflect)]
 #[reflect(Component, PartialEq)]
 pub struct GlobalTransform(Affine3A);
 

crates/bevy_transform/src/components/transform.rs

@@ -34,7 +34,7 @@ use std::ops::Mul;
 ///
 /// [`global_vs_local_translation`]: https://github.com/bevyengine/bevy/blob/latest/examples/transforms/global_vs_local_translation.rs
 /// [`transform`]: https://github.com/bevyengine/bevy/blob/latest/examples/transforms/transform.rs
-#[derive(Component, Debug, PartialEq, Clone, Copy, Reflect)]
+#[derive(Component, Debug, PartialEq, Clone, Copy, Reflect, FromReflect)]
 #[reflect(Component, Default, PartialEq)]
 pub struct Transform {
     /// Position of the entity. In 2d, the last value of the `Vec3` is used for z-ordering.