Add parameter to ListObjectsV2 to make the iteration interruptible

[AlloVince]

Hi guys

Currently the ListObjectsV2 in SDK is not able to start a iteration in halfway, for some small cases it is ok. But in my project, a bucket have over 100k items, if any failing happened, I have to re-start the whole iteration from the first item, it is really unacceptable for a large bucket

According to discussion of issue 6825, go lang core API already had a start-after parameter, I think the SDK should support this too, for example:

var stream = minioClient.listObjectsV2('mybucket','', true)
var lastCursor = null;
stream.on('data', function(obj) { lastCursor = obj.cursor } )

if iteration failed, input cursor as startAfter will continue last task:

var stream = minioClient.listObjectsV2({
  bucket: 'mybucket',
  prefix: '',
  recursive: true,
  startAfter: lastCursor
})

Looking forward for this feature, this is really important, thanks.

[kannappanr]

@AlloVince Thanks for filing the issue here. We will try to implement this feature soon.