Show taxonomy visibility information in the REST API

[pento]

In order to determine whether to show the meta box for a taxonomy, Gutenberg needs to know its show_ui setting.

While we're adding that, lets expose all of the visibility settings.

[pento]

Gutenberg references:

​https://github.com/WordPress/gutenberg/issues/2450
​https://github.com/WordPress/gutenberg/pull/2654

[TimothyBlynJacobs]

I don't think the context conditional is required there, it should be stripped out of non edit contexts by the controller in filter_response_by_context().

[joehoyle]

Added a clean patch and also added JSON Schema for the visibility properties, description taken from the WP documentation.

[omarreiss]

Anything blocking this from being committed?

[pento]

In 42729:

REST API: Show taxonomy visibility settings.

For Gutenberg and other admin-type interfaces, it's useful to be able to see the visibility settings for taxonomies.

Props joehoyle, pento.
Fixes #42707.

[TimothyBlynJacobs]

Strings aren't translated?

[pento]

Whee!

[pento]

In 42730:

REST API: Translate the taxonomy visibility description strings.

This was missed in [42729].

Props TimothyBlynJacobs.
Fixes #42707.

[schlessera]

There's a typo in the first description string:

'The visibility settings for the taxomonmy.'

Should be:

'The visibility settings for the taxonomy.'

[danielbachhuber]

42707.3.diff fixes the typo

[pento]

In 42973:

REST API: Fix a typo introduced in [42729].

Props danielbachhuber.
Fixes #42707.

[danielbachhuber]

Re-opening for backporting against the 5.0 branch.

[danielbachhuber]

As it turns out, part of this landed in r43445: https://core.trac.wordpress.org/changeset/43445/branches/4.9/src/wp-includes/rest-api/endpoints/class-wp-rest-taxonomies-controller.php

42707.4.diff is an application of the remainder against the 5.0 branch.

[danielbachhuber]

In 43680:

REST API: Define taxonomy visibility settings in schema

For Gutenberg and other admin-type interfaces, it's
useful to be able to see the visibility settings for
taxonomies.

The original changeset was partially included in [43445].

Merges [42729], [42730], [42973] to the 5.0 branch.
Props joehoyle, TimothyBlynJacobs, pento.
Fixes #42707