Retrying failed HTTP requests

Hi :)

We're trying to recover from cases where an HTTP request may fail due to bad network conditions (which may arise on mobile).

I've looked into ways to achieve that natively using Cesium, but I haven't found much regarding this.

Would you have pointers to help us implement that the proper way via Cesium Native?

For now, we're considering performing the retries directly in the `HttpAssetAccessor`.

Thanks for helping