yuzu: create linux group in general settings

- Create files dedicated to starting and stopping gamemode functions
  - Use them in yuzu and yuzu_cmd modules

src/common/settings.cpp

@@ -219,6 +219,8 @@ const char* TranslateCategory(Category category) {
         return "Services";
     case Category::Paths:
         return "Paths";
+    case Category::Linux:
+        return "Linux";
     case Category::MaxEnum:
         break;
     }