Add common states "Empty" and "Full" (home-assistant#146646)

Author: NoRi2909

homeassistant/strings.json

@@ -128,9 +128,11 @@
       "disabled": "Disabled",
       "discharging": "Discharging",
       "disconnected": "Disconnected",
+      "empty": "Empty",
       "enabled": "Enabled",
       "error": "Error",
       "fault": "Fault",
+      "full": "Full",
       "high": "High",
       "home": "Home",
       "idle": "Idle",