Poll the server for any pending device commands.

💾 This method alters the persisted account state.

Applications that have registered one or more `DeviceCapability`s with the server can use this method to check whether other devices on the account have sent them any commands. It will return a list of `IncomingDeviceCommand` structs for the application to process.

Notes

• Device commands are typically delivered via push message and the `CommandReceived`(

• AccountEvent::CommandReceived) event. Polling should only be used as a backup delivery mechanism, f the application has reason to believe that push messages may have been missed.

• Device commands functionality is only available to applications that have been granted the https://identity.mozilla.com/apps/oldsync scope.