[feat] Limit heat_cool mode adjustments

[gorstj]

Is it possible to limit the maximum adjustment of each component of the heat_cool mode

Currently we can limit the minimum and the maximum through min_temp: 14 max_temp: 18

This essentially stops someone disabling the heating by setting a very low temperature (e.g. 10) or disabling the A/C by setting a high temp (e.g. 35).

However, is it possible to have a setting that prevents someone setting a very low A/C temperature e.g. limit it to 20 (don't want someone setting it below 20) Or limit the heating temperature to e.g. 21 (don't want someone heating to above 21)

Hope this makes sense and I am not missing an obvious config entry!