fix #1171 && Improve message recall handling and cleanup

Changed recallMsg to return the result of the event call. Added a 5-second cache cleanup for recall events in DeleteMsg. Removed an unnecessary blank line in plugin.ts.

src/onebot/action/msg/DeleteMsg.ts

@@ -16,6 +16,9 @@ class DeleteMsg extends OneBotAction<Payload, void> {
     async _handle(payload: Payload) {
         const msg = MessageUnique.getMsgIdAndPeerByShortId(Number(payload.message_id));
         if (msg) {
+            this.obContext.recallEventCache.set(msg.MsgId, setTimeout(() => {
+                this.obContext.recallEventCache.delete(msg.MsgId);
+            }, 5000));
             await this.core.apis.MsgApi.recallMsg(msg.Peer, msg.MsgId);
         } else {
             throw new Error('Recall failed');