Eurom Wall Design Heat 2000: remove legacy type

History:
1) User reports new device, mistakenly identified from website as
   Eurom Sani Wall Heat 2000, and config made
2) From further comments device properly identified as Wall Design Heat
3) File renamed and legacy_type tag used to keep backwards compatibility
4) PR made for actual Sani Wall Heat 2000

With 4, the legacy type tags should have been removed.

Annoyingly these configs differ only in the presets spelling, and are otherwise
compatible, but cannot be merged due to the different spelling used.

custom_components/tuya_local/devices/eurom_saniwallheat2000_heater.yaml

@@ -1,4 +1,5 @@
-name: Eurom Sani-Wall-Heat 2000 Wifi heater
+name: Heater
+# products: id unknown, name: Eurom Sani-Wall-Heat 2000
 primary_entity:
   entity: climate
   translation_only_key: heater

custom_components/tuya_local/devices/eurom_walldesignheat2000_heater.yaml

@@ -1,5 +1,5 @@
-name: Eurom wall Designheat 2000 heater
-legacy_type: eurom_saniwall2000_heater
+name: Heater
+# products: id unknown, name: Eurom wall Designheat 2000 heater
 primary_entity:
   entity: climate
   translation_only_key: heater