[Protocol] Implement generic response with dyn (#56)

* Implement generic response as enum

* First draft of implementing into_common()

* Make common response type generic

* Use macros and generics to reduce repetition

* [Games] Add dynamically dispatched CommonResponse trait

This adds two traits: "CommonResponse", and "CommonPlayer", when the
generic game query function returns a response it returns a pointer to
its original response type that implements "CommonResponse".

Both common traits require that "as_original()" be implemented, this
returns an enum containing a pointer to the original type.

Both traits have a concrete method "as_json()" that returns a struct
containing data fetched from all of its methods as. This struct
implements serde and can hence be serialized as required.

The traits require a few other methods be implemented, those being the
fields that are common across all types. All other methods have a
default None implementation so that each response type only needs to
implement methods for fields that it has.

* [Game] Implement common traits for JCMP2 response

* [Fmt] Run cargo fmt

* Fix doctest failing

* Run cargo fmt

src/protocols/quake/two.rs

@@ -1,13 +1,15 @@
 use crate::protocols::quake::client::{client_query, remove_wrapping_quotes, QuakeClient};
 use crate::protocols::quake::one::QuakeOne;
 use crate::protocols::quake::Response;
-use crate::protocols::types::TimeoutSettings;
+use crate::protocols::types::{CommonPlayer, GenericPlayer, TimeoutSettings};
 use crate::{GDError, GDResult};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 use std::net::SocketAddr;
 use std::slice::Iter;
 
+use super::QuakePlayerType;
+
 /// Quake 2 player data.
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
@@ -17,6 +19,19 @@ pub struct Player {
     pub name: String,
 }
 
+impl QuakePlayerType for Player {
+    fn version(response: &Response<Self>) -> super::VersionedResponse {
+        super::VersionedResponse::TwoAndThree(response)
+    }
+}
+
+impl CommonPlayer for Player {
+    fn as_original(&self) -> GenericPlayer { GenericPlayer::QuakeTwo(self) }
+
+    fn name(&self) -> &str { &self.name }
+    // TODO: Maybe frags is score?
+}
+
 pub(crate) struct QuakeTwo;
 impl QuakeClient for QuakeTwo {
     type Player = Player;