User: Add name and image URL (#6008)

* User: Add name and image URL

More personalization options, prerequisite for btcpayserver/app#3.

Additionally:
- Remove ambigious and read-only username from manage view.
- Improve email verification conditions and display.
- Greenfield: Update current user. Prerequisite for btcpayserver/app#13.

* Refactor UpdateCurrentUser

* Replace new columns by UserBlob

* Update email check and add test case for mailbox addresses

---------

Co-authored-by: nicolas.dorier <nicolas.dorier@gmail.com>

BTCPayServer/Models/ServerViewModels/UsersViewModel.cs

@@ -1,7 +1,9 @@
 using System;
 using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 using BTCPayServer.Data;
 using BTCPayServer.Services.Stores;
+using Microsoft.AspNetCore.Http;
 
 namespace BTCPayServer.Models.ServerViewModels
 {
@@ -10,8 +12,12 @@ namespace BTCPayServer.Models.ServerViewModels
         public class UserViewModel
         {
             public string Id { get; set; }
-            public string Name { get; set; }
             public string Email { get; set; }
+            public string Name { get; set; }
+
+            [Display(Name = "Image")]
+            public IFormFile ImageFile { get; set; }
+            public string ImageUrl { get; set; }
             public bool? EmailConfirmed { get; set; }
             public bool? Approved { get; set; }
             public bool Disabled { get; set; }
@@ -20,13 +26,13 @@ namespace BTCPayServer.Models.ServerViewModels
             public IEnumerable<string> Roles { get; set; }
             public IEnumerable<UserStore> Stores { get; set; }
         }
-        public List<UserViewModel> Users { get; set; } = new List<UserViewModel>();
+        public List<UserViewModel> Users { get; set; } = [];
         public override int CurrentPageCount => Users.Count;
         public Dictionary<string, string> Roles { get; set; }
     }
     public class RolesViewModel : BasePagingViewModel
     {
-        public List<StoreRepository.StoreRole> Roles { get; set; } = new List<StoreRepository.StoreRole>();
+        public List<StoreRepository.StoreRole> Roles { get; set; } = [];
         public string DefaultRole { get; set; }
         public override int CurrentPageCount => Roles.Count;
     }