feat(ContainerClient): add proxy utility

[mayooot]

fix: apple/container#466

[jglogan]

@mayooot you need to run make fmt on your branch

[jglogan]

@mayooot lgtm, but one last thing - you'll need to set up a signing key and force push the change one last time with a signed commit; see https://docs.github.com/en/authentication/managing-commit-signature-verification/telling-git-about-your-signing-key

Once that's done, we can merge the change and tag as 0.7.1 so you can use it for the kernel download fix in container.

[jglogan]

It's still blocking the PR because only the merge commit is signed.

You that you have signed commits set up, could you soft reset your branch back to the base, make a single signed commit for the change, and then force push that over the existing branch? That should allow us to merge. Sorry for the inconvenience, and thank you for the contribution!

[mayooot]

It's still blocking the PR because only the merge commit is signed.

You that you have signed commits set up, could you soft reset your branch back to the base, make a single signed commit for the change, and then force push that over the existing branch? That should allow us to merge. Sorry for the inconvenience, and thank you for the contribution!

Oops, the PR was closed when I reset my branch back to the unchanged state 😢 . I can't reopen it, so I've already opened another PR. Could you review the new PR or reopen the old one?