Essentials thermostat _TZE200_i48qyn9s

[TAKeanice]

Reopen of #4909 (with adaptations, especially removing the schedule, that should make the PR acceptable). Resolves Koenkk/zigbee2mqtt#14239

[Koenkk]

Thanks!

Could you also submit a picture for the docs? This can be done by:

1. Create a fork by clicking here
2. Go to the public/images/devices directory, Add file -> Upload files
3. Upload the files and press Commit changes
4. Press Contribute -> Open pull request -> update title/description -> Create pull request

Make sure that:

• The filename is _TZE200_i48qyn9s.png
• The size is 512x512
• The background is transparent (use e.g. Adobe remove background)

[Koenkk]

Thanks!