Json refactor + quiet + id option

[lap1nou]

Greetings,

This PR aims to simplify the source code by putting all reverse shells in JSON files so it's easier to read the source code and it split the logic of the generation from the payloads itself.

I also added two parameters --quiet which only output the payload and nothing else and --id which can be used to specifiy which exact payload we want in output.

This is useful to combine it with an xclip for example where it will directly copy the payload in the clipboard:

shellerator.py -t netcat --id netcat1 --quiet --lhost 127.0.0.1 --lport 443 | xclip

This can also be useful to create alias for very common payload:

alias nc-rev="shellerator.py -t netcat --id netcat1 --quiet --lhost 127.0.0.1 --lport 443 | xclip"

Regards.