Refactor use statements to enable building Windows

[jsturtevant]

This PR does not enable windows features but it does make it so the shim will build on Windows. This will make the following PR's smaller and easier to digest to do it in steps. It also makes it easier while other changes go in without having to rebase complex changes.

one small step towards #49

For now this disables dead-code and unused imports but should be turned on before in following PR's as functionality is added.

Todo in the PR:
Add a CI

• job that validates the build on windows.

[jsturtevant]

The CI is passing 🥳

I've opened #240, #239 to make this PR smaller and easier to review. Since #226 is close to merging I would suggest we get these merged and that would also make this PR much smaller and simpler.

[jprendes]

Thanks for working in this :-).
I think native windows support would add a lot of value.

I haven't finished, but here are my comments so far.

Also, I'm not a big fan of the new cfg_window / cgf_unix macros.
I think they add a lot of cyclomatic complexity to the code.
I would much prefer to create separate os-specific modules, and factor out the code that differs between each os.

[jsturtevant]

latest failure was the outofspace we are seeing on other PRs:

 Warning  FailedCreatePodSandBox  43s   kubelet            Failed to create pod sandbox: rpc error: code = Unknown desc = failed to create containerd container: failed to create prepare snapshot dir: mkdir /var/lib/containerd/io.containerd.snapshotter.v1.overlayfs/snapshots/new-3941906082/fs: no space left on device

[jsturtevant]

Also, I'm not a big fan of the new cfg_window / cgf_unix macros.
I think they add a lot of cyclomatic complexity to the code.
I would much prefer to create separate os-specific modules, and factor out the code that differs between each os.

@jprendes I cleaned this up where it made sense. In some cases, I believe its easier to read if it is in-lined but let me know what you think. The one last place I would like to do this is around the mounting code but I don't know the abstraction to put in place just yet. I've started this on the Windows side but haven't full flushed it out but will follow up on moving it to an abstraction in the next PR.

[jsturtevant]

/assign @Mossaka @jprendes @cpuguy83

[jsturtevant]

test failure is #252

[cpuguy83]

LGTM!

[jprendes]

Thanks, this is looking great!
Looking forward to having this merged :-)

[Mossaka]

LGTM!!

[Mossaka]

lgtm!

[jsturtevant]

looks like a different issue with ubuntu 22.04, now that storage has been solved.

[Mossaka]

Cool, shall I merge this in? @jsturtevant