Added primitive search mechanism in backend.

Began implementing search mechanism for frontend.

Props-Modules/Props.Shop/Framework/IShop.cs

@@ -12,10 +12,10 @@ namespace Props.Shop.Framework
         string ShopDescription { get; }
         string ShopModuleAuthor { get; }
 
-        public IAsyncEnumerable<ProductListing> Search(string query, Filters filters);
+        public IEnumerable<ProductListing> Search(string query, Filters filters);
 
-        IEnumerable<IOption> Initialize(byte[] data);
+        void Initialize(string workspaceDir);
+        Task InitializeAsync(string workspaceDir);
         public SupportedFeatures SupportedFeatures { get; }
-        public byte[] GetDataForPersistence();
     }
 }

Props-Modules/Props.Shop/Framework/ProductListing.cs

@@ -1,6 +1,6 @@
 namespace Props.Shop.Framework
 {
-    public struct ProductListing
+    public class ProductListing
     {
         public float LowerPrice { get; set; }
         public float UpperPrice { get; set; }