Lang guess: Support learn.wordpress.org

[renyot]

Currently lang guess doesn't handle the request from learn.wordpress.org, making it not able to render a language guess banner on learn sites.

Closes ​https://github.com/WordPress/Learn/issues/2428

The locale information for Learn comes from the query parameter locale rather than the subdomain, so this PR retrieves the locale and sends it to lang-guess for processing.

lang-guess corresponding tweaks: meta.trac.wordpress.org/ticket/7675

[renyot]

Tickets: ​https://github.com/WordPress/Learn/issues/2428
wporg-mu-plugins corresponding PR: ​https://github.com/WordPress/wporg-mu-plugins/pull/626

[Otto42]

Nice patch. Does the banner show up properly?

[renyot]

Thanks. Yes, there are some screenshots in this ​PR

[renyot]

r22222-dotorg:

Lang guess: Support learn.wordpress.org.

See ​https://meta.trac.wordpress.org/ticket/7675

It looks like this triggers a notice now, I'm seeing this on my local env:

Notice: Function wp_enqueue_script was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. This notice was triggered by the language-suggest-front handle. Please see Debugging in WordPress for more information.