impl Eq/PartialEq for MeshMaterial{2|3}d (#17990)

# Objective

`Eq`/`PartialEq` are currently implemented for `MeshMaterial{2|3}d` only
through the derive macro. Since we don't have perfect derive yet, the
impls are only present for `M: Eq` and `M: PartialEq`. On the other
hand, I want to be able to compare material components for my toy
reactivity project.

## Solution

Switch to manual `Eq`/`PartialEq` impl.

## Testing

Boy I hope this didn't break anything!

Author: jnhyatt

crates/bevy_pbr/src/mesh_material.rs

@@ -36,7 +36,7 @@ use derive_more::derive::From;
 ///     ));
 /// }
 /// ```
-#[derive(Component, Clone, Debug, Deref, DerefMut, Reflect, PartialEq, Eq, From)]
+#[derive(Component, Clone, Debug, Deref, DerefMut, Reflect, From)]
 #[reflect(Component, Default)]
 pub struct MeshMaterial3d<M: Material>(pub Handle<M>);
 
@@ -46,6 +46,14 @@ impl<M: Material> Default for MeshMaterial3d<M> {
     }
 }
 
+impl<M: Material> PartialEq for MeshMaterial3d<M> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+impl<M: Material> Eq for MeshMaterial3d<M> {}
+
 impl<M: Material> From<MeshMaterial3d<M>> for AssetId<M> {
     fn from(material: MeshMaterial3d<M>) -> Self {
         material.id()

crates/bevy_sprite/src/mesh2d/material.rs

@@ -186,7 +186,7 @@ pub trait Material2d: AsBindGroup + Asset + Clone + Sized {
 /// ```
 ///
 /// [`MeshMaterial2d`]: crate::MeshMaterial2d
-#[derive(Component, Clone, Debug, Deref, DerefMut, Reflect, PartialEq, Eq, From)]
+#[derive(Component, Clone, Debug, Deref, DerefMut, Reflect, From)]
 #[reflect(Component, Default)]
 pub struct MeshMaterial2d<M: Material2d>(pub Handle<M>);
 
@@ -196,6 +196,14 @@ impl<M: Material2d> Default for MeshMaterial2d<M> {
     }
 }
 
+impl<M: Material2d> PartialEq for MeshMaterial2d<M> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+impl<M: Material2d> Eq for MeshMaterial2d<M> {}
+
 impl<M: Material2d> From<MeshMaterial2d<M>> for AssetId<M> {
     fn from(material: MeshMaterial2d<M>) -> Self {
         material.id()