Publish box timestamp form elements initial focus

[afercia]

In the Post Publish box, when opening the timestamp expandable div, focus is moved to the "Month" select. This is correct when the language set is English.
Turns out translators can swap the fields to adapt them to their locale date format, for example see the Italian publish box in the screenshot below:

I guess Italian is not the only case and we shouldn't assume the Month select will always be the first form element.

[afercia]

Proposed patch moves focus to the first, visible, input or select element.

[afercia]

Noticed that sometimes screen readers have issues when focus is moved to elements that are still not fully visible. Focus should always be moved when the animation has completed. Will open a new ticket for this.

[iseulde]

Why input:visible?

[afercia]

Replying to iseulde:

Why input:visible?

There are some hidden inputs in the timestamp div, just wanted to be sure to exclude them. And yes they come after so :visible maybe is unnecessary but who knows maybe some future markup change could place some hidden inputs before. On the other hand, targeting the inner .timestamp-wrap would mean getting one more element. Oh well maybe I'm overthinking, feel free to change it and keep it simple if you think that would be better :)

[iseulde]

@afercia Does this look good?

[iseulde]

In 33349:

Publish box: focus first date field on edit

The order of the fields may change depending on the translation.

Props afercia.
Fixes #33059.