GuestLog - User message improvements

- Added UserMessageService to have common methods for showing messages and errors to the user.
- Added Result record so services can return status on operation error (so it can be shown in the UI messages).
- Updated services to use the new Result record.
- Updated pages to use the new IUserMessageService.

src/Somnia.GuestLog/Components/Pages/GuestDocuments/GuestDocNew.razor

@@ -4,7 +4,7 @@
 @using Somnia.GuestLog.Services;
 @using Somnia.GuestLog.Validators;
 
-@inject ISnackbar Snackbar
+@inject IUserMessageService userMessage
 @inject IDialogService DialogService
 @inject NavigationManager Navigation
 @inject IGuestDocumentService guestDocService
@@ -129,26 +129,25 @@
         bool isFormValid = await _form.ValidateForm();
         if (!isFormValid)
         {
-            Snackbar.Add("Invalid Form!", Severity.Error);
+            userMessage.ShowMessage("Invalid Form!", MessageKind.Warning);
             return;
         }
 
         GuestDocumentDTO model = _form.Model;
 
-        Snackbar.Add($"Document '{model.DocumentNum}' creating...", Severity.Info);
-
         //Show Loading dialog...
         var loadingDialog = await DialogService.ShowAsync<LoadingDialog>();
 
-        bool isCreated = await guestDocService.CreateDocumentAsync(model);
-        if (!isCreated)
+        Result createResult = await guestDocService.CreateDocumentAsync(model);
+        if (!createResult.IsSuccess)
         {
-            Snackbar.Add($"Error creating Document '{model.DocumentNum}'", Severity.Error);
+            string errorMsg = $"Error creating Document '{model.DocumentNum}'";
+            userMessage.ShowResultWithMessage(createResult, errorMsg);
             loadingDialog.Close();
             return;
         }
 
-        Snackbar.Add($"Document '{model.DocumentNum}' Created!", Severity.Success);
+        userMessage.ShowMessage($"Document '{model.DocumentNum}' Created!", MessageKind.Success);
         Navigation.NavigateTo(GuestConsts.Page_GuestDocs_List);
     }
 
@@ -156,7 +155,7 @@
     {
         if (currentPageMode != ePageMode.alreadyExistDoc)
         {
-            Snackbar.Add("Invalid operation!", Severity.Error);
+            userMessage.ShowMessage("Invalid operation!", MessageKind.Error);
             return;
         }