feat(eventbus): implement event handling for ticket and conversation assignments

internal/services/event_handlers/registry.go

@@ -0,0 +1,11 @@
+package event_handlers
+
+import "sync"
+
+var registerOnce sync.Once
+
+func Register() {
+	registerOnce.Do(func() {
+		registerWxWorkNotifyEventHandlers()
+	})
+}