FromTemplate for TilemapChunkTileData

[rendaoer]

In Tilemap usage, TilemapChunk implements FromTemplate, so it can be used directly. However, TilemapChunkTileData cannot; it must be wrapped in a template before use.

bsn! { 
    TilemapChunk { 
        chunk_size: chunk_size, 
        tile_display_size: tile_display_size, 
        tileset: { tileset.clone() }, 
        alpha_mode: AlphaMode2d::default(), 
    }
    template(|_| TilemapChunkTileData(tile_data.clone())) 
}

Similar to the previous FontSize PR (#23724), it can be used after modification

bsn! { 
    TilemapChunk { 
        chunk_size: chunk_size, 
        tile_display_size: tile_display_size, 
        tileset: { tileset.clone() }, 
        alpha_mode: AlphaMode2d::default(), 
    } 
    TilemapChunkTileData({ tile_data.clone() }) 
}