No progress if executed over ssh

If I run s4cmd via ssh I see no progress, but if I go in and manually disable these lines:

```
if not (sys.stdout.isatty() and sys.stderr.isatty()):
return
```

I see the progress just fine. Wondering if it would be possible to introduce a --progress option to force progress even if sys.stdout.isatty() is False.

Start by locating the CLI argument handling and the progress code containing the sys.stdout.isatty() and sys.stderr.isatty() checks. Run s4cmd over SSH to reproduce the missing progress, then verify that the requested --progress behavior works when output is not attached to a TTY.

Written by the indexing model from the issue text.