fix(qrlogin): import token after migration

[tie]

This change fixes the DC migration in qrlogin package.

If, however, there is a DC mismatch between the two apps, auth.loginTokenMigrateTo is returned instead, to which the app that is trying to login should respond by calling auth.importLoginToken with the specified token, to the specified DC.
https://core.telegram.org/api/qr-login

[codecov]

Codecov Report

Merging #993 (100513d) into main (12cd7ff) will increase coverage by 0.08%.
The diff coverage is 6.66%.

@@            Coverage Diff             @@
##             main     #993      +/-   ##
==========================================
+ Coverage   69.57%   69.66%   +0.08%     
==========================================
  Files         444      444              
  Lines       21193    21201       +8     
==========================================
+ Hits        14746    14770      +24     
+ Misses       5506     5499       -7     
+ Partials      941      932       -9     

Impacted Files	Coverage Δ
telegram/auth/qrlogin/errors.go	0.00% <ø> (ø)
telegram/auth/qrlogin/qrlogin.go	61.76% <6.66%> (-8.45%)	⬇️
tgtest/handle.go	40.19% <0.00%> (+2.94%)	⬆️
internal/proto/codec/intermediate.go	100.00% <0.00%> (+4.91%)	⬆️
tgtest/loop.go	70.00% <0.00%> (+5.00%)	⬆️
tgtest/send.go	59.45% <0.00%> (+5.40%)	⬆️
internal/mtproto/write.go	91.89% <0.00%> (+8.10%)	⬆️
transport/connection.go	73.52% <0.00%> (+8.82%)	⬆️
internal/mtproto/salt.go	86.66% <0.00%> (+13.33%)	⬆️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more