implement bit shift node

[Vizonex]

I read the old pull request from 6 years ago that attempted to implement integer packing and with my desire to write a new socks5 parser soon that parses negotiation packets on both the client and server's end as part of RFC1928 I knew that doing so would not be an easy task. Currently It requires some functionality that llparse currently doesn't implement. My goal here is to change that entirely as I understand llparse's code architecture pretty well as I have made a python parody of this library already.

Goals with this Pull Request

• To revive the llparse typescript library as a whole as well as add a few new features to it so that llparse can continue receiving maintenance.

• Provide a new node that is small and be easy to maintain

• Have actual tests provided to increase the likelihood of these features being added in.

• A tool which I named ShiftChecker named after the LoopChecker is also provided to

  • validate Shift nodes for missing fields
  • check for integer sizes that could overflow the parser state's fields
  • check for inappropriate fields that can't be shifted into such as the ptr type.

This solution provides the ability to pack bytes and it simplifies @arthurschreiber's original work and makes the implementation smaller.

The reason I would like for a llsocks5 library to use typescript however is because more people know how to use llparse in the typescript language which means I could be possibly given outside help as well as better feedback which is why I am doing this all to begin with. I might also look into making an smtp parser even though my understanding of the smtp protocol isn't as good as my understanding with the socks5 protocol is which is why I am working on a new socks5 parser first.

closes #1