Add more info to site health message "The authorization header is missing"

[Presskopp]

In case this message is shown, you'll have the option to Flush permalinks. But there is no information why one should do so and what to expect. I'd like to add some info there like

"You can try..." or "If this doesn't help you may need to contact your hosting provider" etc.

Here's a related ticket that well describes the situation: #52487

[Clorith]

Good shout out!

I am thinking this entire response could probably be improved a little, perhaps something along these lines:

The Authorization header is used by third-party applications you have approved for this site. Without this header, those apps cannot connect to your site.

If you are still seeing this warning after having tried the actions below, you may need to contact your hosting provider for further assistance.

The second paragraph about contacting your host would only be shown if the header is missing, while the first paragraph is a slight re-wording of the existing text to make it a bit clearer

[webcommsat]

In response to the copy review requested in dev chat. Thanks @Clorith.
The revised text is clearer. Is there an explanation of Authorization Header in the glossary which we could link to for those users who receive this error message but are less familiar with the term? Thanks.

[Clorith]

I don't think we have one like that, @webcommsat.

I'm thinking the use case here is with Application Passwords, so perhaps we could look into getting a HelpHub article about that area of WordPress, which could be linked to?
(I had a look at the ​Glossary page, and that's too much information in one page to send a potential non-technical user to in my opinion, if that's the page you were referencing)

I don't know how feasible it would be to get a new HelpHub article up before beta, but adding an action button as a followup to this ticket is also an approach we could easily take, to help move things along :)

Trac ticket: https://core.trac.wordpress.org/ticket/54508

[Clorith]

In 54196:

Site Health: Improve the description for Authorization header checks.

Previously the description left the user stuck with no path forward if flushing their permalinks was not enough.

This change givers a clearer description of what approving an application may involve (allowing these to connect to the users site), but also an additional step towards resolution if flushing permalinks are not enough; pointing them towards their host.

Props Presskopp, webcommsat.
Fixes #54508.

Added in changeset b10d8771fb09d521c17e7255b9cc9d4930a78712