[enhancement] Add special char in password lookup

Hi, I'm forking your ansible-keepass module for install it with ansible galaxy. During my rewrite, I add the support of special characters and think it could interest you. We have just change the alphabet to alphabet = string.ascii_letters + string.digits + string.punctuation.

If you want to see what we've done, it's right here.

EDIT : private repository while I working on it, send me a message and I'll give you the permission :)