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.Client/Models/UpdateApplicationUserRequest.cs

@@ -0,0 +1,29 @@
+namespace BTCPayServer.Client.Models;
+
+public class UpdateApplicationUserRequest
+{
+    /// <summary>
+    /// the name of the user
+    /// </summary>
+    public string Name { get; set; }
+
+    /// <summary>
+    /// the image url of the user
+    /// </summary>
+    public string ImageUrl { get; set; }
+
+    /// <summary>
+    /// the email AND username of the user
+    /// </summary>
+    public string Email { get; set; }
+
+    /// <summary>
+    /// current password of the user
+    /// </summary>
+    public string CurrentPassword { get; set; }
+
+    /// <summary>
+    /// new password of the user
+    /// </summary>
+    public string NewPassword { get; set; }
+}