refactor: modify the default format in chat module to support playe…

…r nickname + add: nickname module + refactor: now `realname module` will list all players with nickname

src/main/java/io/github/sakurawald/config/model/ChatModel.java

@@ -10,7 +10,7 @@ public class ChatModel {
     public class Format {
         public HashMap<String, String> player2format = new HashMap<>() {
             {
-                this.put("SakuraWald", "<#FFC7EA>%message%");
+                this.put("Steve", "<#FFC7EA>%message%");
             }
         };
     }