support configuring asset settings in BSN

## What problem does this solve or what need does it fill?

It would be nice to be able to configure loader settings with asset in BSN.

## What solution would you like?

```rust
Something like this:
bsn! {
TilemapChunk {
tileset: asset_with_settings(
"images/tileset.png",
|settings: &mut ImageLoaderSettings| {
// ...
}
),
chunk_size: { chunk_size },
tile_display_size: UVec2::splat(20),
}
}
```

## What alternative(s) have you considered?

After further consideration, I think using a meta file seems like a good alternative. But we may need a way to write the customized loader settings to meta file more than a default one.

## Additional context

I have tried to add a new variant in `HandleTemplate` and the associated helper function.

```rust
enum HandleTemplate {
// ...
PathWithSettings(AssetPath<'static>, Arc, PhantomData),
}
```

But the it is referenced in `AssetApp::register_asset_reflect` as `type_registry.register::>();`

I'm not sure what is the proper workaround for it.

Start by reading the BSN asset example and the HandleTemplate references, especially AssetApp::register_asset_reflect and its type registration. Compare the proposed asset_with_settings approach with the meta-file alternative. Done means the supported design for customized loader settings is established and works through BSN without breaking asset reflection.

Written by the indexing model from the issue text.