bevy_reflect: Add clone registrations project-wide

[MrGVSV]

Objective

Now that #13432 has been merged, it's important we update our reflected types to properly opt into this feature. If we do not, then this could cause issues for users downstream who want to make use of reflection-based cloning.

Solution

This PR is broken into 4 commits:

1. Add #[reflect(Clone)] on all types marked #[reflect(opaque)] that are also Clone. This is mandatory as these types would otherwise cause the cloning operation to fail for any type that contains it at any depth.

2. Update the reflection example to suggest adding #[reflect(Clone)] on opaque types.

3. Add #[reflect(clone)] attributes on all fields marked #[reflect(ignore)] that are also Clone. This prevents the ignored field from causing the cloning operation to fail.

   Note that some of the types that contain these fields are also Clone, and thus can be marked #[reflect(Clone)]. This makes the #[reflect(clone)] attribute redundant. However, I think it's safer to keep it marked in the case that the Clone impl/derive is ever removed. I'm open to removing them, though, if people disagree.

4. Finally, I added #[reflect(Clone)] on all types that are also Clone. While not strictly necessary, it enables us to reduce the generated output since we can just call Clone::clone directly instead of calling PartialReflect::reflect_clone on each variant/field. It also means we benefit from any optimizations or customizations made in the Clone impl, including directly dereferencing Copy values and increasing reference counters.

   Along with that change I also took the liberty of adding any missing registrations that I saw could be applied to the type as well, such as Default, PartialEq, and Hash. There were hundreds of these to edit, though, so it's possible I missed quite a few.

That last commit is massive. There were nearly 700 types to update. So it's recommended to review the first three before moving onto that last one.

Additionally, I can break the last commit off into its own PR or into smaller PRs, but I figured this would be the easiest way of doing it (and in a timely manner since I unfortunately don't have as much time as I used to for code contributions).

Testing

You can test locally with a cargo check:

cargo check --workspace --all-features

[bushrat011899]

Good bit of maintenance. A Bevy CLI tool to automatically lint against missing reflected traits can't come soon enough!

[MrGVSV]

Good bit of maintenance. A Bevy CLI tool to automatically lint against missing reflected traits can't come soon enough!

Yep I was wanting to work on one. We'll see if I can do that before 0.17 is out 😅