Add icons for shade device class (#7493)

The blinds material icon looks more like a shade
then a blind but since its already being used
blind its still better than having it look like
a window.

src/common/entity/cover_icon.ts

@@ -43,6 +43,7 @@ export const coverIcon = (state?: string, stateObj?: HassEntity): string => {
       }
     case "blind":
     case "curtain":
+    case "shade":
       switch (state) {
         case "opening":
           return "hass:arrow-up-box";