feat(discount): add InStock filter to discount product queries and mappings

- Introduced InStock property to GetDiscountProductsQuery and GetCustomerProductsByFilterQuery for filtering based on product availability.
- Updated query handlers to apply InStock filtering logic in both discount and customer product queries.
- Enhanced mapping configurations to include InStock in the response DTOs.
- Bumped Protobuf project version to reflect the addition of new features.

src/CMSMicroservice.Protobuf/CMSMicroservice.Protobuf.csproj

@@ -3,7 +3,7 @@
     <TargetFramework>net9.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <Version>0.0.203</Version>
+    <Version>0.0.204</Version>
     <DebugType>None</DebugType>
     <DebugSymbols>False</DebugSymbols>
     <GeneratePackageOnBuild>False</GeneratePackageOnBuild>

src/CMSMicroservice.Protobuf/Protos/products.proto

@@ -229,6 +229,7 @@ message GetAllProductsByFilterFilter
     google.protobuf.Int32Value remaining_count = 13;
     google.protobuf.Int64Value category_id = 14;
     google.protobuf.BoolValue is_active = 15;
+    google.protobuf.BoolValue in_stock = 16;
 }
 message GetAllProductsByFilterResponse
 {