fix(ts-protocol): drop self-echoed text messages

TeamSpeak echoes a bot's own channel/server messages back to itself.
Without filtering, a chunked reply re-entered the command path: !help's
output exceeds the ~1024-byte per-message cap, so splitTextIntoChunks
splits it, and the second chunk (which starts with "!artist ...") was
parsed as a new !artist command, loading 20 search results and starting
playback.

Drop messages whose invokerID matches the bot's own clientId at the
transport boundary, before they reach any consumer.

src/ts-protocol/client.ts

@@ -222,6 +222,7 @@ export class TS3Client extends EventEmitter {
     });
 
     this.client.on("textMessage", (msg: TextMessage) => {
+      if (msg.invokerID === this.clientId) return;
       this.emit("textMessage", toTS3TextMessage(msg));
     });