add a basic event system to clean up scoresaber score receiving

src/main/java/cc/fascinated/bat/service/EventService.java

@@ -0,0 +1,40 @@
+package cc.fascinated.bat.service;
+
+import cc.fascinated.bat.event.EventListener;
+import cc.fascinated.bat.features.scoresaber.ScoreSaberScoreFeedListener;
+import lombok.NonNull;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.stereotype.Service;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * @author Fascinated (fascinated7)
+ */
+@Service @Log4j2
+public class EventService {
+    /**
+     * The list of listeners registered
+     */
+    public static final Set<EventListener> LISTENERS = new HashSet<>();
+
+    @Autowired
+    public EventService(@NonNull ApplicationContext context) {
+        registerListeners(
+                context.getBean(ScoreSaberScoreFeedListener.class)
+        );
+        log.info("Registered {} listeners.", LISTENERS.size());
+    }
+
+    /**
+     * Registers an event listener
+     *
+     * @param listener the listener to register
+     */
+    public void registerListeners(EventListener... listener) {
+        LISTENERS.addAll(Set.of(listener));
+    }
+}