Move Training code to .Net Core

[ACoderLife]

The UI will not be able to run on .NET Core,
but the trainer code can, making the training possible on a linux cluster, maybe.

[ACoderLife]

I cannot say we can target .NET Core since some of the libraries we might use in the future
might not support it
but there is a mix of netstandard and .net framework
we could target
aiming to have the cli trainer runnable on .net core, as the best outcome