Improve 2FA autofill

[Jonher937]

This improves the autofill suggestion on mobile devices and some password managers.
I got the ideas of those changes from this article from Twilio

It seems to improve autofilling in both mobile devices and desktop password managers as tested in Issue #15403

[codecov-commenter]

Codecov Report

Merging #16473 (3056d91) into main (ec35783) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main   #16473      +/-   ##
==========================================
- Coverage   45.43%   45.42%   -0.02%     
==========================================
  Files         717      717              
  Lines       84184    84184              
==========================================
- Hits        38252    38243       -9     
- Misses      39780    39790      +10     
+ Partials     6152     6151       -1     

Impacted Files	Coverage Δ
services/mailer/mail_comment.go	77.77% <0.00%> (-7.41%)	⬇️
modules/process/manager.go	72.83% <0.00%> (-2.47%)	⬇️
modules/notification/mail/mail.go	36.27% <0.00%> (-1.97%)	⬇️
modules/git/blame.go	65.71% <0.00%> (-1.43%)	⬇️
services/pull/pull.go	41.93% <0.00%> (-0.44%)	⬇️

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