[Checkout] Prevent extra fields when login in on addressing page

[Jibbarth]

Q	A
Branch?	1.12
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Related tickets	fixes #15183
License	MIT

Refs video in #15183

When we login in addressing page after submit once the page, the reload process after login resubmit data, and keep sending form[customer][email], that it doesn't be added in form.

So I unset these data on pre-submit.
I also change the csrf_error message for something more "understandable".

By this way, we can still have previous submitted data for address fields.

The other way, suggested by @Wojdylak, is to change this line https://github.com/Sylius/Sylius/blob/1.12/src/Sylius/Bundle/UiBundle/Resources/private/js/sylius-api-login.js#L50
by

window.location = window.location.href;

But using it, all already filled data are lost.

WDYT ? Would it be acceptable to lose such data, or should we keep them ?

[github-actions]

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[vvasiloi]

Hey @Jibbarth, thanks for your contribution! I left some feedback. Could you also add a test for it?

[Jibbarth]

Thanks for the review @vvasiloi. I will try to make a test 🤞

Tests have been added :)

[jakubtobiasz]

Thank you, @Jibbarth!