Describe the bug
When running nxc smb ... --groups, passing an NT hash via -H will
result in a usage error, despite that being supported for other
subcommands like --users.

This is due to the Pywerview library's behavior when given an NT hash by
itself - it expects to find LM:NT, not simply NT. This is not called for
most nxc smb ... commands, but is for --groups. The CLI utility
bundled with Pywerview compensates by prepending a dummy LM: before
calling the library, but NetExec does not do so. Using options such as --users,
takes a different code path that does not reference the block of code in requester.py
that is used for --groups.

The following was tested with NetExec 1.3.0 (NeedForSpeed - Kali Linux)
and PywerView 0.3.3.

To Reproduce
Steps to reproduce the behavior:
Command: netexec smb <TARGET> -u <USERNAME> -H <HASH> --groups
Resulted in:

SMB         <IP REDACTED>    445    <HOST REDACTED>     [-] Error enumerating domain group using dc ip <IP REDACTED>: NTLM needs domain\username and a password

Expected behavior
The command should successfully enumerate groups as it does when enumerating users
(i.e. --users).

NetExec info

• OS: Kali
• Version of nxc: NetExec 1.3.0 (NeedForSpeed - Kali Linux)
• Installed from: Apt package manager - netexec/kali-rolling,now 1.3.0-0kali2

Additional context
A workaround for the problem is to supply a generic LM hash or random
combination of hex characters 32 bytes in length before the NT hash.
Both of the following commands results in successful enumeration of groups:

nxc smb <TARGET> -u "Administrator" -H "aad3b435b51404eeaad3b435b51404ee:<NTHASH>" --groups"

nxc smb <TARGET> -u "Administrator" -H "abcdabcdabcdabcdabcdabcdabcdabcd:<NTHASH>" --groups

This works because connection.py validates the NTLM hash by looking at the length.

As another workaround, we can do similar to what Pywerview's own CLI does,
by checking each provided hash argument; if it is a plain single hash,
prepend a dummy LM: to the string. With this in
place, --users and other methods still work fine (they will use the
NT half of an LM:NT argument), and --groups works as well.
A proof-of-concept fix will be submitted as a PR.