[zstdcli] Add --no-progress flag

The `--no-progress` flag disables zstd's progress bars, but leaves
the summary.

I've added simple tests to `playTests.sh` to make sure the parsing
works.

programs/zstd.1.md

@@ -195,6 +195,8 @@ the last one takes effect.
 * `-q`, `--quiet`:
     suppress warnings, interactivity, and notifications.
     specify twice to suppress errors too.
+* `--no-progress`:
+    do not display the progress bar, but keep all other messages.
 * `-C`, `--[no-]check`:
     add integrity check computed from uncompressed data (default: enabled)
 * `--`: