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/Services/UserService.cs

@@ -49,6 +49,7 @@ namespace BTCPayServer.Services
 
         public static ApplicationUserData FromModel(ApplicationUser data, string?[] roles)
         {
+            var blob = data.GetBlob() ?? new();
             return new ApplicationUserData
             {
                 Id = data.Id,
@@ -58,6 +59,8 @@ namespace BTCPayServer.Services
                 Approved = data.Approved,
                 RequiresApproval = data.RequiresApproval,
                 Created = data.Created,
+                Name = blob.Name,
+                ImageUrl = blob.ImageUrl,
                 Roles = roles,
                 Disabled = data.LockoutEnabled && data.LockoutEnd is not null && DateTimeOffset.UtcNow < data.LockoutEnd.Value.UtcDateTime
             };