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/AddressQueryDialog.razor

@@ -1,9 +1,10 @@
 @using Somnia.GuestLog.Models.DTOs;
+@using Somnia.GuestLog.Services
 @using Somnia.GuestLog.Services.AddressQuery;
 
 @inject ILogger<AddressQueryDialog> logger;
 @inject IAddressQueryFactory addressQueryFactory;
-@inject ISnackbar Snackbar
+@inject IUserMessageService userMessage
 
 <MudDialog @ref="@DialogRef">
     <TitleContent>
@@ -112,7 +113,7 @@
         catch (Exception ex)
         {
             logger.LogError(ex, "SearchAddress returned an error!");
-            Snackbar.Add($"Error searching address: {ex.Message}", Severity.Error);
+            userMessage.ShowMessage($"Error searching address: {ex.Message}", MessageKind.Error);
         }
     }
 
@@ -120,7 +121,7 @@
     {
         if (SelectedAddressResult is null)
         {
-            Snackbar.Add("Select an address", Severity.Warning);
+            userMessage.ShowMessage("Select an address", MessageKind.Warning);
             return;
         }