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/Controls/GuestDocumentSearchDialog.razor

@@ -2,7 +2,7 @@
 @using Somnia.GuestLog.Services
 
 @inject ILogger<AddressQueryDialog> logger;
-@inject ISnackbar Snackbar
+@inject IUserMessageService userMessage
 @inject IGuestDocumentService guestDocumentService;
 
 
@@ -108,7 +108,7 @@
         catch (Exception ex)
         {
             logger.LogError(ex, "GuestDocument Search returned an error!");
-            Snackbar.Add($"Error searching: {ex.Message}", Severity.Error);
+            userMessage.ShowMessage($"Error searching: {ex.Message}", MessageKind.Error);
         }
     }
 
@@ -119,7 +119,7 @@
     {
         if (filter.IsEmpty)
         {
-            Snackbar.Add("Add some search!", Severity.Warning);
+            userMessage.ShowMessage("Search can't be empty!", MessageKind.Warning);
             return;
         }
 
@@ -131,7 +131,7 @@
     {
         if (SelectedResult is null)
         {
-            Snackbar.Add("Select a guest document", Severity.Warning);
+            userMessage.ShowMessage("A guest document must be selected", MessageKind.Warning);
             return;
         }