[API Request] Expose Assets.currentAssetMapping.assetList as IReadOnlyList<Asset>.

[DanielWillett]

Currently it's pretty inefficient and inconvenient to loop through assets, a copy has to be made using Assets.find<>() or by passing a list, either way could be quite a bit easier by exposing a readonly list property so we can easily use Linq to find assets without having to go through all the trouble of managing a second list, etc.

Also shouldn't really have to worry about future changes since it should be fairly easy to port over to any asset system.

public class Assets
{
    // ...

    public static IReadOnlyList<Asset> LoadedAssets => Assets.currentAssetMapping.assetListReadOnly;

    // ...


    internal class AssetMapping
    {
        // ...
        public IReadOnlyList<Asset> assetListReadOnly;

        public AssetMapping()
        {
           // ...
           assetListReadOnly = assetList.AsReadOnly();
        }
    }
}