Extract suggestion and vote workflows into services

Program.cs

@@ -34,6 +34,8 @@ else if (!Path.IsPathRooted(connectionBuilder.DataSource))
 var connectionString = connectionBuilder.ToString();
 
 builder.Services.AddDbContext<AppDbContext>(options => options.UseSqlite(connectionString));
+builder.Services.AddScoped<SuggestionWorkflowService>();
+builder.Services.AddScoped<VoteWorkflowService>();
 
 builder.Services.ConfigureHttpJsonOptions(options => { options.SerializerOptions.Converters.Add(new JsonStringEnumConverter()); });