[AC-2488] Add billing endpoint to determine SM standalone for organization (#4014)

* Add billing endpoint to determine SM standalone for org.

* Add missing attribute

src/Api/Billing/Controllers/OrganizationBillingController.cs

@@ -0,0 +1,27 @@
+using Bit.Api.Billing.Models.Responses;
+using Bit.Core.Billing.Queries;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Bit.Api.Billing.Controllers;
+
+[Route("organizations/{organizationId:guid}/billing")]
+[Authorize("Application")]
+public class OrganizationBillingController(
+    IOrganizationBillingQueries organizationBillingQueries) : Controller
+{
+    [HttpGet("metadata")]
+    public async Task<IResult> GetMetadataAsync([FromRoute] Guid organizationId)
+    {
+        var metadata = await organizationBillingQueries.GetMetadata(organizationId);
+
+        if (metadata == null)
+        {
+            return TypedResults.NotFound();
+        }
+
+        var response = OrganizationMetadataResponse.From(metadata);
+
+        return TypedResults.Ok(response);
+    }
+}