Move inferno-ml-server to this repo

[ngua]

Moves most of the things related to inferno-ml-server to this repo, including:

• the inferno-ml-server Haskell package
• the base NixOS modules and image configurations
• the server nixosTest

There are no changes to inferno-ml-server itself beyond some minor renaming in some places, updated comments, etc...

To make it easier to extend the image configurations, I've also added an image-config flake input. This should contain additional NixOS modules to include in the image configuration (they will be automatically included). For this repo, we don't need any additional config, so it's set to a new nix/dummy directory. But it can be overridden elsewhere. I've tried this out with a different repo and it works nicely

I've also included some of the Python packages that I made for training. These aren't strictly related to inferno-ml-server but they might be useful to have here (we also have devShells..pytorch already, so it's in the same vein as that). If we really don't want them we can put them somewhere else

I also noticed that the flake was getting a bit out of control, so I split everything into smaller modules. There's a comment in the flake explaining the new structure. This does not affect actually using the flake -- it's just for internal organization to make things nicer and more maintainable/readable

[siddharth-krishna]

Looks good, but I notice that some test files seem to be duplicated, e.g. nix/inferno-ml/tests/models/mnist.ts.pt is also at inferno-ml/test/mnist.ts.pt -- is it possible to de-duplicate?

[ngua]

@siddharth-krishna Oh, good catch, I guess those are from renaming/moving some things. I'll remove the redundant ones

[siddharth-krishna]

Thanks, but I notice we still have two mnist.ts.pt files.. I was hoping to keep the repo size down

[ngua]

@siddharth-krishna I only see one at nix/inferno-ml/tests/models/mnist.ts.pt, where is the other one?

[siddharth-krishna]

My bad, I must not have read the find-grep output properly!