Those plugins re really simple and don't need any initialization logic.
With the using statement, we do not need to add a constructor and pass the parent/args to the baseclass
- We do not need the return type. If a plugin declares it can handle the
packet it should do so. We don't have any fallback logic in place and
the packet types are namespaced with the plugin IDs anyway.
- Provide a default implementation with a warning, not all plugins need
to overwrite this
