Ecostrad Accent iQ: update to modern conventions
This was quite an old config, and had some issues:
- timer was implemented as numeric, but was actually using strings, so
should be select (may be causing compatibility issues).
- temperature_unit was present, but not settable (Byecold info says it is rw)
- Top level name was product specific. Now that another brand and model is
confirmed to match, this has been fixed.
Product ids are not available for either the Ecostrad or the Byecold model,
so products can only be added as comments for now.
Issue #2551