Aquatech Rapid: remove gratuitous icons

Almost every attribute had an icon associated, without priorities which
would conflict with each other.  It seems to be a misunderstanding of
how icon support works.  Default icon should be OK for this device, so
removed all.

custom_components/tuya_local/devices/aquatech_x6_water_heater.yaml

@@ -13,19 +13,14 @@ primary_entity:
           conditions:
             - dps_val: ECO
               value: eco
-              icon: "mdi:cash"
             - dps_val: Stand
               value: heat_pump
-              icon: "mdi:heat-pump"
             - dps_val: HYB
               value: high_demand
-              icon: "mdi:sun-thermometer"
             - dps_val: HYB1
               value: performance
-              icon: "mdi:radiator"
             - dps_val: ELE
               value: electric
-              icon: "mdi:heating-coil"
     - id: 2
       type: string
       name: work_mode
@@ -37,22 +32,15 @@ primary_entity:
         min: 15
         max: 75
       readonly: true
-      icon: "mdi:thermometer-lines"
     - id: 7
       type: boolean
       name: defrosting
-      mapping:
-        - dps_val: true
-          icon: "mdi:snowflake-melt"
-        - dps_val: false
-          icon: "mdi:checkbox-blank-off-outline"
     - id: 15
       type: bitfield
       name: fault_code
     - id: 16
       type: integer
       name: current_temperature
-      icon: "mdi:thermometer-water"
 secondary_entities:
   - entity: binary_sensor
     class: problem