Fetch authlib-injector metadata on startup

HMCLCore/src/main/java/org/jackhuang/hmcl/auth/authlibinjector/AuthlibInjectorServer.java

@@ -218,6 +218,11 @@ public class AuthlibInjectorServer implements Observable {
         return this.url.equals(another.url);
     }
 
+    @Override
+    public String toString() {
+        return name == null ? url : url + " (" + name + ")";
+    }
+
     @Override
     public void addListener(InvalidationListener listener) {
         helper.addListener(listener);