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/ManageViewModels/IndexViewModel.cs

@@ -1,21 +1,20 @@
 using System.ComponentModel.DataAnnotations;
+using Microsoft.AspNetCore.Http;
 
 namespace BTCPayServer.Models.ManageViewModels
 {
     public class IndexViewModel
     {
-        public string Username { get; set; }
-
-
         [Required]
         [EmailAddress]
         [MaxLength(50)]
-        public string Email
-        {
-            get; set;
-        }
-
-        public bool IsEmailConfirmed { get; set; }
+        public string Email { get; set; }
+        public bool EmailConfirmed { get; set; }
+        public bool RequiresEmailConfirmation { get; set; }
+        public string Name { get; set; }
 
+        [Display(Name = "Profile Picture")]
+        public IFormFile ImageFile { get; set; }
+        public string ImageUrl { get; set; }
     }
 }