Generate Hot Rod parser automatically

This JIRA has two objectives:
1. reduce number of allocated objects
2. improve the parsing on server side to avoid chains of lambda mappings

Manual parsing of Hot Rod protocol, invoking recursive methods that return {{Optional}}s or {{Optional<Optional<...>}}s seems to generate a lot of garbage. A better approach would be a finite state automaton that would read the byte stream and invoke callbacks.

Such automaton can be generated from a high-level grammar as part of the build process.

Along with these changes we can remove the Response abstraction and write responses directly as {{ByteBuf}}s.