[PM-16684] Integrate Pricing Service behind FF (#5276)

* Remove gRPC and convert PricingClient to HttpClient wrapper

* Add PlanType.GetProductTier extension

Many instances of StaticStore use are just to get the ProductTierType of a PlanType, but this can be derived from the PlanType itself without having to fetch the entire plan.

* Remove invocations of the StaticStore in non-Test code

* Deprecate StaticStore entry points

* Run dotnet format

* Matt's feedback

* Run dotnet format

* Rui's feedback

* Run dotnet format

* Replacements since approval

* Run dotnet format

src/Core/Core.csproj

@@ -27,12 +27,6 @@
     <PackageReference Include="AWSSDK.SQS" Version="3.7.400.85" />
     <PackageReference Include="Azure.Data.Tables" Version="12.9.0" />
     <PackageReference Include="Azure.Extensions.AspNetCore.DataProtection.Blobs" Version="1.3.4" />
-    <PackageReference Include="Google.Protobuf" Version="3.29.2" />
-    <PackageReference Include="Grpc.Net.Client" Version="2.67.0" />
-    <PackageReference Include="Grpc.Tools" Version="2.68.1">
-      <PrivateAssets>all</PrivateAssets>
-      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
-    </PackageReference>
     <PackageReference Include="Microsoft.AspNetCore.DataProtection" Version="8.0.10" />
     <PackageReference Include="Azure.Messaging.ServiceBus" Version="7.18.1" />
     <PackageReference Include="Azure.Storage.Blobs" Version="12.21.2" />
@@ -78,11 +72,7 @@
     <PackageReference Include="System.Text.Json" Version="8.0.5" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="8.0.1" />
   </ItemGroup>
-
-  <ItemGroup>
-    <Protobuf Include="Billing\Pricing\Protos\password-manager.proto" GrpcServices="Client" />
-  </ItemGroup>
-
+  
   <ItemGroup>
     <Folder Include="Resources\" />
     <Folder Include="Properties\" />