Identity scaffold template missing encoding when verifying via login page

[StickMick]

Describe the bug

The Identity scaffold template has several ways to trigger the email verification, but one is missing encoding.
.../V3/Account/Login.cshtml.cs

OnPostSendVerificationEmailAsync()
...
var code = await _userManager.GenerateEmailConfirmationTokenAsync(user);
//Missing
code = WebEncoders.Base64UrlEncode(Encoding.UTF8.GetBytes(code));
//End Missing
var callbackUrl = Url.Page(

Verification process will always decode, so un-encoded links will fail.

To Reproduce

Steps to reproduce the behavior:

1. Using this version of ASP.NET Core 3
2. Create project with local account storage
3. Scaffold Identity
4. Implement IEmailSender
5. Create Account
6. Logout
7. Use Resend Verification Email from login page
8. Follow link in second email - it will fail.
9. Follow link in first email - it will succeed.

Expected behavior

All email verification links to be encoded for email, then decoded on submit.

[HaoK]

This is somewhat related to #13462, we can discuss at triage today

[HaoK]

Using this bug to track removing all vestiges of resend email in 3.1, it will be brought back in better form in 5.0

[HaoK]

Removed the feature in 3.1 #14901 scaffolding side of the removal is here dotnet/Scaffolding#1117