Add support for @aws-sdk/client-s3

[alvin-nt]

This is an attempt to add support for @aws-sdk/client-s3 (AWS SDK v3). If merged, this PR should resolve #241

[zandaqo]

But AWS SDK V3 doesn't have headObject function? S3Client doesn't have the said methods, S3 class does, though, it doesn't have the send method, hence, the PR still breaks.

[ChrisZieba]

hmm, yea I gave this a try and it doesn't seem to work out. What if you did something like

try {
   return client.headObject(params).promise()
} catch(e) {
   if (e.msg === 'something') {
        return client.headObject(params).then()
   }
}

[ChrisZieba]

@alvin-nt thanks for opening this PR, do you have the bandwidth to add this tweak or should I give it a shot?

[alvin-nt]

Hi. Apologies for the long reply. Due to life circumstances, I could not continue this PR yet. If you may, please give a shot to fix my code.

[obones]

Wouldn't it be enough to change isAwsSdkV3 to this:

            const isAwsSdkV3 = typeof client.send === "function";

Here, at least, it gives true with v3 and false with v2

[rgiovani]

Hi, Maybe we can do something like:

    if (isAwsSdkV3) {
          return client.send(new HeadObjectCommand(params)).then(function (res) {
            return res.ContentLength;
          });
    }

[ZJONSSON]

Thanks @alvin-nt and sorry for the long delay. I'm being more active in managing this repo and your PR is now deviating from master. Can you rebase and clean it up so it's only reflecting the s3 change and no other changes

Thanks again!