feat: add player name configuration and rename config file

- Add --player command-line argument and 'player' field in Arguments struct
- Rename ip.toml to server.toml and corresponding internal variable to 'server'
- Fix block.cpp source path in CMakeLists.txt

include/Cubed/app.hpp

@@ -16,6 +16,7 @@ public:
         bool is_client = false;
         int port = 25530;
         std::string ip{"127.0.0.1"};
+        std::string player{"Unknown"};
     };
 
     App();