Recognize LANcom LCOS software and support ed448 key extraction (#277)

* Include raw hostkey bytes in debug output

* Recognize LANcom LCOS software and support extraction of ssh-ed448 key type

LANcom router devices appear to be primarily used in Germany (see [1]
for examples on the public Internet), and they appear to support the
`ssh-ed448` key type which is documented in [2], but which has never
been supported by any as-yet-released version of OpenSSH.

[1] https://www.shodan.io/search?query=ssh+%22ed448%22
[2] https://datatracker.ietf.org/doc/html/rfc8709#name-public-key-format

src/ssh_audit/software.py

@@ -224,4 +224,8 @@ class Software:
         mx = re.match(r'^PuTTY_Release_(.*)', software)
         if mx:
             return cls(None, Product.PuTTY, mx.group(1), None, None)
+        mx = re.match(r'^lancom(.*)', software)
+        if mx:
+            v, p = 'LANcom', 'LCOS sshd'
+            return cls(v, p, mx.group(1), None, None)
         return None