refactor universe process logic

[LouisSzeto]

No description provided.

[AlexCatarino]

Let's return a boolean, and return false with the exception.

[AlexCatarino]

Please undo this comment.
We need to check if it's a success for both and return exit(1) if one fails

var success = instance.Run();
if  (!success)
{
    Log.Error($"QuantConnect.DataProcessing.Program.Main(): Failed to download/process {CoinGeckoUniverseDataDownloader.VendorName} data");
}
if (!instance.GenerateUniverseFiles())
{
    Log.Error($"QuantConnect.DataProcessing.Program.Main(): Failed to generate {CoinGeckoUniverseDataDownloader.VendorName} universe");
   success = false:
}
if (!success) Environment.Exit(1);