print error added pehash

When the command “pe pehash” was used, no feedback was provided when no
session was opened. Now it prints that there is no session opened when
used without args and it prints the PEhash of the file when a session is opened and no arguments are provided.

Also adjusted the help menu usage from "[hac]" to "[hacs"] adding the -s of scan argument

The other rule commitments are from the viper update changes and are not related.
The changes apply to rules:
854, and 882+883