[PM-26793] Fetch premium plan from pricing service (#6450)

* Fetch premium plan from pricing service

* Run dotnet format

src/Api/Billing/Controllers/PlansController.cs

@@ -0,0 +1,28 @@
+using Bit.Api.Models.Response;
+using Bit.Core.Billing.Pricing;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Bit.Api.Billing.Controllers;
+
+[Route("plans")]
+[Authorize("Web")]
+public class PlansController(
+    IPricingClient pricingClient) : Controller
+{
+    [HttpGet("")]
+    [AllowAnonymous]
+    public async Task<ListResponseModel<PlanResponseModel>> Get()
+    {
+        var plans = await pricingClient.ListPlans();
+        var responses = plans.Select(plan => new PlanResponseModel(plan));
+        return new ListResponseModel<PlanResponseModel>(responses);
+    }
+
+    [HttpGet("premium")]
+    public async Task<IResult> GetPremiumPlanAsync()
+    {
+        var premiumPlan = await pricingClient.GetAvailablePremiumPlan();
+        return TypedResults.Ok(premiumPlan);
+    }
+}