Enhance user plan management and update related endpoints

- Added new configuration options for user plans in `.env.example`, including `Plans__MaxCustomConfigCount` and `Plans__MinCustomConfigCount`.
- Introduced `MapPlanEndpoints` in `Program.cs` to handle plan-related API routes.
- Implemented `SetUserPlan` endpoint in `RoleEndpoints` to allow admins to assign plans to users.
- Removed deprecated role request approval endpoints from `AdminSupportEndpoints`.
- Updated `ITelegramNotifier` and related classes to reflect changes in role request handling and payment notifications.
- Refactored role management commands to remove `MaxConfigs` and focus on `MaxIpLimit` and billing settings.
- Enhanced billing request handling to accommodate plan changes instead of role changes.
- Updated various interfaces and command handlers to support new plan management features.

backend/tests/PnvPanel.Application.Tests/Admin/Billing/ListPaymentRequestsQueryHandlerTests.cs

@@ -17,7 +17,7 @@ public class ListPaymentRequestsQueryHandlerTests
         using var dbContext = InMemoryDbContextFactory.Create();
         var userId = Guid.NewGuid();
         var subscription = PaymentRequest.Create(userId, PaymentPeriod.Quarter, 1500);
-        var topUp = PaymentRequest.CreateRoleChangeTopUp(userId, 500);
+        var topUp = PaymentRequest.CreatePlanChangeTopUp(userId, 500);
         dbContext.PaymentRequests.AddRange(subscription, topUp);
         await dbContext.SaveChangesAsync(CancellationToken.None);
 
@@ -30,7 +30,7 @@ public class ListPaymentRequestsQueryHandlerTests
         var result = await handler.Handle(
             new ListPaymentRequestsQuery(
                 StatusFilter: null,
-                KindFilter: PaymentRequestKind.RoleChangeTopUp,
+                KindFilter: PaymentRequestKind.PlanChangeTopUp,
                 Search: null,
                 Page: 1,
                 PageSize: 20