♻️ refactor(agora): adjust import method for agora-token module

- change default import to named import to fix potential module import issues
- use object destructuring to maintain access to RtcTokenBuilder, RtmTokenBuilder and RtcRole

src/server/modules/agora/agora-token.service.ts

@@ -1,4 +1,5 @@
-import { RtcTokenBuilder, RtmTokenBuilder, RtcRole } from 'agora-token'
+import pkg from 'agora-token';
+const {RtcTokenBuilder, RtmTokenBuilder, RtcRole} = pkg;
 
 export class AgoraTokenService {
   private appId: string