feat: add --binary(-b) option to hash commands (#5885)

For instance,

```
echo 'abcdefghijklmnopqrstuvwxyz' | hash sha256 --binary
```

Will returns the hash as a binary value instead of a hexadecimaly encoded string.

crates/nu-command/src/strings/encode_decode/decode_base64.rs

@@ -23,7 +23,7 @@ impl Command for DecodeBase64 {
             )
             .switch(
                 "binary",
-                "do not decode payload as UTF-8 and output binary",
+                "Output a binary value instead of decoding payload as UTF-8",
                 Some('b'),
             )
             .rest(