[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/Api/Controllers/SelfHosted/SelfHostedOrganizationLicensesController.cs

@@ -64,7 +64,8 @@ public class SelfHostedOrganizationLicensesController : Controller
 
         var result = await _organizationService.SignUpAsync(license, user, model.Key,
             model.CollectionName, model.Keys?.PublicKey, model.Keys?.EncryptedPrivateKey);
-        return new OrganizationResponseModel(result.Item1);
+
+        return new OrganizationResponseModel(result.Item1, null);
     }
 
     [HttpPost("{id}")]