gb: use "Game Boy" save path for both GB and GBC

Fixes using the same rom file on both GB and GBC hardware without losing save-data between them
Fixes Pokemon Stadium when loading a .gbc rom (the Transfer Pak only used the GB path)

Existing users using a custom save game path will have to manually move their saves from "Game Boy Color" to "Game Boy"
Users using the default "Save alongside rom files" will not have to take any action.

mia/medium/game-boy-color.cpp

@@ -1,4 +1,5 @@
 struct GameBoyColor : GameBoy {
   auto name() -> string override { return "Game Boy Color"; }
+  auto saveName() -> string override { return "Game Boy"; }
   auto extensions() -> vector<string> override { return {"gb", "gbc"}; }
 };

mia/pak/pak.cpp

@@ -149,7 +149,7 @@ auto Pak::saveLocation(string location, string name, string extension) -> string
   string saveLocation;
   if(auto path = mia::saveLocation()) {
     //if the user has chosen a specific location to save files to ...
-    saveLocation = {path, this->name(), "/", Location::prefix(location), extension};
+    saveLocation = {path, this->saveName(), "/", Location::prefix(location), extension};
   } else if(directory::exists(location)) {
     //if this is a pak ...
     saveLocation = {location, name};

mia/pak/pak.hpp

@@ -4,6 +4,7 @@ struct Pak {
   virtual ~Pak() = default;
   virtual auto type() -> string { return pak->attribute("type"); }
   virtual auto name() -> string { return pak->attribute("name"); }
+  virtual auto saveName() -> string { return pak->attribute("name"); }
   virtual auto extensions() -> vector<string> { return {}; }
   virtual auto load(string location = {}) -> LoadResult { return successful; }
   virtual auto loadMultiple(vector<string> location = {}) -> bool { return true; }