Normalized derives for bevy/serde features

[piedoom]

Some nodes were missing derives or weren't implementing reflect/serde. I used the derives in delay_compensation as a guide. The exception is the sampler node, as ArcGc doesn't have the necessary derives, so I left that off. (Maybe it can be safely skipped? I'm not sure how to handle the smart pointers here)

[BillyDM]

Ok, thanks!

I don't think serde/reflection would make sense for the ArcGc pointers since it requires a garbage collector instance to be constructed. And furthermore it wouldn't make sense for the sampler node because you wouldn't want to serde/reflect the entire audio file resource.

I suppose we could skip the ArcGc field. The user just has to make sure they fill in the sample resource manually later.

[piedoom]

Thanks! Updated sampler to fit your comments.