Improve address save flow to allow to use custom validators

[vovayatsyuk]

This is a copy of my previous PR: #7552. I've made some very bad things there, and I had to restart PR 😞

I'm facing an issue, that I cannot make some fields optional because of hardcoded
validation of address fields. Moreover, validation is made in private method, so I can't use plugin for it.

Hopefully, there is a public validation method analogue, available in address class, that can be extended with plugins.

[vrann]

@vovayatsyuk Please check this PR #8519: it fixes the similar issue of certain attributes being required. If it solves the same issue of some fields being required.

Also, can you provide more details on how do you make those fields optional?

[vrann]

@vovayatsyuk please merge the PR with the latest develop branch

[vovayatsyuk]

1. Merged. While merging, I've noticed that mine PR is already merged. I think that the Improve address save flow to allow to use custom validators #7552 was merged before.
2. I've made optional fields with address-field-manager. (It uses the same approach as Magento use for customer prefix, suffix, and other configurable address attributes)

[vrann]

@vovayatsyuk Hi, Pull Request now has 0 Files changed after your last commit. Can you please check what happened? You might overwritten your changes by the mainline.

[vovayatsyuk]

It is because my changes where already merged by magento team:

801c121
bd7eecf

I think there is no point to keep this ticket active. Should I close it?

[vrann]

@vovayatsyuk yes, please

[orlangur]

@vrann I've noticed in a couple of processed pull requests already that some guys are not using Git properly.

Here you can see that cde83ef commit is present in mainline as 801c121. So, somebody did inappropriate rebase which changed the hash of initial commit. With proper Git usage this PR would be marked as Merged without any additional actions.

Cc: @okorshenko, @maghamed, @ishakhsuvarov

[vovayatsyuk]

@orlangur it was me :(

In my previous PR I've made a mistake and decided to create another one. But someone from magento team already applied my changes from the first PR internally. So this PR become empty as soon as my original commit from the first PR was pushed to dev branch and I merged it in here.

p.s. I'll be careful next time..

[orlangur]

Oh :) That's totally unexpected. Sorry guys for disturbing you, I overlooked the probability of force push by PR author.