refactor: rename Api project to Web

- HrynCo.NotificationService.Api -> HrynCo.NotificationService.Web
- HrynCo.NotificationService.Api.IntegrationTests -> HrynCo.NotificationService.Web.IntegrationTests
- Updated slnx, docker-compose, project references, and namespaces
- Project serves both REST API and admin UI

Ref: IT-628

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

HrynCo.NotificationService.Web/Controllers/EmailChannels/UpdateEmailChannelRequest.cs

@@ -0,0 +1,12 @@
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+
+namespace HrynCo.NotificationService.Web.Controllers.EmailChannels;
+
+public sealed record UpdateEmailChannelRequest(
+    int Priority,
+    EmailChannelSettings Settings,
+    int? DailyLimit,
+    int? MonthlyLimit,
+    int WarnThresholdPercent,
+    bool IsActive
+);