chore(PocketIC): PocketIC library build on Windows

[mraszyk]

This PR adds a GitHub CI flow for PocketIC library build on Windows.

[cgundy]

Another question is whether this needs to be part of the release workflow. If so, you would need to add it like this:
https://github.com/dfinity/ic/blob/master/.github/workflows/release-testing.yml#L23-L26

Though we'd first want to make sure they're very stable so it doesn't block the release pipeline.

[mraszyk]

Another question is whether this needs to be part of the release workflow.

I wouldn't put that on the release pipeline (at least for now).

[cgundy]

Ah actually one more thing - would you mind adding .github/workflows/pocket-ic-build-windows.yml to CODEOWNERS, so you can make changes to it in the future?

[mraszyk]

would you mind adding .github/workflows/pocket-ic-build-windows.yml to CODEOWNERS, so you can make changes to it in the future?

I'm not sure it's needed as I don't expect further changes and I'd appreciate your review anyway if changes are needed after all.