Use ABNF to parse messages from String

[w4ll3]

This would improve maintainability if the message changes, right now Ruby doesn't have a good ABNF parser which makes this parsing quite difficult.

[mculp]

You mean to tell me this 20 year old code isn't suitable? 😂

First time I've seen "20 years ago" in a github repo.

[mculp]

this looks like it is maintained: https://github.com/dryruby/ebnf/blob/develop/examples/abnf/parser.rb