aws s3 ls allows listing by file prefix, but aws s3 sync does not

Hi,

I have an S3 Bucket that has a range of files like this:

```
0000-abcdef-ghiklm-nopqrs
1000-abcdef-ghiklm-nopqrs
2000-abcdef-ghiklm-nopqrs
3000-abcdef-ghiklm-nopqrs
a000-abcdef-ghiklm-nopqrs
b000-abcdef-ghiklm-nopqrs
c000-abcdef-ghiklm-nopqrs
d000-abcdef-ghiklm-nopqrs
```

Each prefix has millions of files in the bucket.

If I want to list files by a prefix, I can do this really efficiently, like so:

* `aws s3 ls s3://my-bucket/1` - Will only list files beginning with `1`
* `aws s3 ls s3://my-bucket/2` - Will only list files beginning with `2`

This is efficient, as it doesn't return any files without the appropriate prefix. The API handles the list, only returning files that start with `1` or `2`

---

The same isn't possible for the `aws s3 sync` command.

`aws s3 sync s3://my-bucket/1* s3://my-new-bucket/` or `aws s3 sync s3://my-bucket/1 s3://my-new-bucket/` does not work.

The only way to do it is through adding a `--exclude` `--include` parameter for example `aws s3 sync s3://my-bucket/ s3://my-new-bucket/ --exclude "*" --include "1*"`

But this is really inefficient, as it lists the whole contents of the bucket, and filters each item to determine whether it should match **client side**. This method makes perfect sense for normal include exclude operations like `--exclude "*" --include "*.txt"` but for prefixed files it is inefficient.

I know that folder/path prefixes should be used, but that isn't always possible. It is clear that the `aws s3 ls` command has the potential to return only files with a specific prefix, so could this behaviour be added into the sync command? Otherwise syncs between buckets take weeks instead of hours.