feat(nbstore): remove async on connection api (#9187)

We should not use async on `connect` and `disconnect`, for `WebSocketConnection` will never connect when offline.

We should handle the connection status of each storage in sync, using the `connection.waitForConnect`

This PR also puts the connection reference count on the `connect` and disconnect`

packages/common/nbstore/src/impls/broadcast-channel/channel.ts

@@ -12,7 +12,7 @@ export class BroadcastChannelConnection extends Connection<BroadcastChannel> {
     return new BroadcastChannel(this.channelName);
   }
 
-  override async doDisconnect() {
+  override doDisconnect() {
     this.close();
   }