Put file from `stdin`

Is it possible to read file from `stdin` with `put`? Since `s3cmd` supports that I tried something like that with `s4cmd` but got error:
```bash
~$ echo foo | s4cmd --endpoint-url https://s3.example.net put - s3://bucketname/test
[OSError] 2: No such file or directory
[Thread Failure] [Errno 2] No such file or directory: '-'
```

Start by tracing the CLI's `put` handling for the `-` source shown in the issue and inspect how it opens the input path. Confirm the expected behavior with the demonstrated `echo foo | s4cmd ... put - s3://bucketname/test` command; done means stdin is accepted and uploaded to the requested S3 destination without the current file-not-found error.

Written by the indexing model from the issue text.