Store display charset on ESPHome

Supports #1359

advanced/esphome/nspanel_esphome_core.yaml

@@ -817,6 +817,12 @@ globals:
     restore_value: true
     initial_value: '0'
 
+  ##### Charset (1 = International (original), 2 = CJK languages)
+  - id: display_charset
+    type: uint
+    restore_value: true
+    initial_value: '0'
+
   ##### Is embedded thermostat set as main climate entity? #####
   - id: is_embedded_thermostat
     type: bool
@@ -1563,6 +1569,15 @@ text_sensor:
                     if (display_mode_float > 0) id(display_mode) = int(display_mode_float);
                   }
 
+                // Detect display charset
+                if (doc.containsKey("charset"))
+                  {
+                    std::string charset_str = doc["charset"];
+                    ESP_LOGV(TAG, "charset: %s", charset_str.c_str());
+                    float charset_float = stof(charset_str);
+                    if (charset_float > 0) id(display_charset) = int(charset_float);
+                  }
+
                 // Contruct page boot
                 page_boot->execute(true);