Improve handling npc sprites

Habitica/src/main/java/com/habitrpg/android/habitica/helpers/AppConfigManager.kt

@@ -36,7 +36,7 @@ class AppConfigManager(contentRepository: ContentRepository?) : com.habitrpg.com
     private val remoteConfig = FirebaseRemoteConfig.getInstance()
 
     fun shopSpriteSuffix(): String? {
-        return worldState?.npcImageSuffix
+        return worldState?.findNpcImageSuffix()
     }
 
     fun maxChatLength(): Long {

Habitica/src/main/java/com/habitrpg/android/habitica/models/WorldState.kt

@@ -21,4 +21,19 @@ open class WorldState : RealmObject(), BaseObject {
 
     @SerializedName("currentEventList")
     var events: RealmList<WorldStateEvent> = RealmList()
+
+    fun findNpcImageSuffix(): String? {
+        if (!npcImageSuffix.isNullOrBlank()) {
+            return npcImageSuffix
+        } else if (!currentEvent?.npcImageSuffix.isNullOrBlank()) {
+            return currentEvent?.npcImageSuffix
+        } else {
+            for (event in events) {
+                if (!event.npcImageSuffix.isNullOrBlank()) {
+                    return event.npcImageSuffix
+                }
+            }
+        }
+        return null
+    }
 }

Habitica/src/main/java/com/habitrpg/android/habitica/ui/views/NPCBannerView.kt

@@ -21,7 +21,10 @@ class NPCBannerView(context: Context, attrs: AttributeSet?) : FrameLayout(contex
 
     var shopSpriteSuffix: String? = null
         set(value) {
-            field = if (value.isNullOrEmpty() || value.startsWith("_")) {
+
+            field = if (value.isNullOrEmpty()) {
+                ""
+            } else if (value.startsWith("_")) {
                 value
             } else {
                 "_$value"