add switch command only if needed

[hpstuff]

I have Avatto smart thermostat. I saw in the log that when the mode is changed {switch: true} command is send every time this was preventing the mode to be set. I've tested it in the tuya device debug to send only the mode command and its work but if you add {switch: true} command (when the device is already on) along with the mode the mode is ignored

[0x5e]

Thanks for the contribution :)

We need a general solution for all devices:

1. Skip send the command for those unchanged.
2. Support send separate command.

Your commit is okay for this specific situation, thanks again.