allow to define set points for embedded heater

This allow to set the upper and lower set point for the embedded thermostat heater. The naming was taken from the HA generic thermostat, i.e. `cold_tolerance` and `hot_tolerance`

nspanel_esphome_addon_climate_heat.yaml

@@ -10,6 +10,8 @@
 substitutions:
   ### Local thermostat defaults ###
   temp_max: "25"
+  cold_tolerance: "0.5"
+  hot_tolerance: "0.5"
 
   ##### DO NOT CHANGE THIS #####
   addon_climate_heat: "true"
@@ -19,6 +21,8 @@ climate:
   - id: !extend thermostat_embedded
     min_heating_off_time: ${min_off_time}s
     min_heating_run_time: ${min_run_time}s
+    heat_deadband: ${cold_tolerance}
+    heat_overrun: ${hot_tolerance}
     heat_action:
       - switch.turn_on: relay_${heater_relay}
     preset: