Support multi address websocket subscriptions

frontend/src/app/interfaces/websocket.interface.ts

@@ -27,6 +27,7 @@ export interface WebsocketResponse {
   fees?: Recommendedfees;
   'track-tx'?: string;
   'track-address'?: string;
+  'track-addresses'?: string[];
   'track-asset'?: string;
   'track-mempool-block'?: number;
   'track-rbf'?: string;