add GetGameCurrency endpoint, add store 8 (empty)

also allowing create empty stores

src/Controllers/Common/ContentController.cs

@@ -1679,10 +1679,17 @@ public class ContentController : Controller {
     [Route("ContentWebService.asmx/GetUserGameCurrency")]
     [VikingSession]
     public IActionResult GetUserGameCurrency(Viking viking) {
-        // TODO: This is a placeholder
         return Ok(achievementService.GetUserCurrency(viking));
     }
 
+    [HttpPost]
+    [Produces("application/xml")]
+    [Route("ContentWebService.asmx/GetGameCurrency")]
+    [VikingSession]
+    public IActionResult GetGameCurrency(Viking viking) {
+        return Ok(achievementService.GetUserCurrency(viking).GameCurrency);
+    }
+
     [HttpPost]
     [Produces("application/xml")]
     [Route("ContentWebService.asmx/SetGameCurrency")] // used by World Of Jumpstart

src/Resources/store.xml

@@ -1949,6 +1949,11 @@ SoD 3.31 main store section and subsection filtering:
 		<ii>1597</ii>
 		<ii>1627</ii>
 	</StoreData>
+	<StoreData>
+		<i>8</i>
+		<s>FL Avatar Default</s>
+		<d>The default avatar parts for Adventure Land -- empty</d>
+	</StoreData>
 	<StoreData>
 		<i>9</i>
 		<s>Main Street_Threadz</s>

src/Services/StoreService.cs

@@ -19,12 +19,14 @@ public class StoreService {
             List<ItemData> itemsList = new();
             IEnumerable<ItemsInStoreDataSale>? memberSales = s.SalesAtStore?.Where(x => x.ForMembers == true);
             IEnumerable<ItemsInStoreDataSale>? normalSales = s.SalesAtStore?.Where(x => x.ForMembers == false || x.ForMembers == null);
+            if (s.ItemId != null) {
                 for (int i = 0; i < s.ItemId.Length; ++i) {
                     ItemData item = itemService.GetItem(s.ItemId[i]);
                     if (item is null) continue; // skip removed items
                     itemsList.Add(item);
                     UpdateItemSaleModifier(item, memberSales, normalSales);
                 }
+            }
             foreach (int itemID in moddingService.GetStoreItem(s.Id)) {
                 ItemData item = itemService.GetItem(itemID);
                 itemsList.Add(item);