Add OIDC Auth0 extended tutorial

[sberyozkin]

This PR adds an extended OIDC Auth0 tutorial, originally it was meant to be a blog post but after discussing with @maxandersen we agreed to make it a tutorial.

This is not a typical tutorial because there is no quickstart, it is meant to show how both code flow and bearer Auth0 tokens can be managed, how Quarkus OIDC can deal with Auth0 specific constraints, how to adapt the code etc.

This tutorial is meant to be the first one in the series dedicated to specific providers, as opposed to simple quickstarts showing some OIDC features in isolation

[github-actions]

🙈 The PR is closed and the preview is expired.

[sberyozkin]

Converting to draft until #36110 is merged - as this PR misses some integration testing instructions - we cover how we can use Dev UI to test but a bit more content is needed re the testing

[sberyozkin]

Hi @michelle-purcell Thanks for starting a review, I'm just about to push an update related to the integration testing, but I'll pick up the suggestions you have already made too

[sberyozkin]

@michelle-purcell I've done a couple of minor updates based on your feedback so far, please have a look tomorrow or so, thanks

[sberyozkin]

I've significantly reworked Access token and token propagation sections, showing Auth0 API, audience, scope to PermissionAllowed conversion. This draft sticks to the echo:name scope, I've used echo.name in tests due to #36313 - but it can be fixed easily early next week; the reason I'm using echo:name in this doc is because Auth0 likes it more, it works with echo.name but fails to show its description in the authorization screen

[sberyozkin]

Hi @gastaldi - can you please consider giving this doc a read during the next few days ? Michelle did a very comprehensive review of may be up to 1/4 of the doc, but she is away and will likely have to be catching up with other urgent doc issues when she returns. I think we can iterate with the Doc team on keeping aligning the text with the guidelines, and optimizing it. I wonder if fixing the obvious text typos or strangely expressed sentences would do for now, I'd not mind at all to try to get it in 3.5.0, the sooner it can become public for users to start working with it the better.
FYI, I've verified the actual steps twice, and can do a 3rd round once the review is complete.
Np at all if you won't find time, we'll get it over the line sooner or later :-)

[sberyozkin]

There should be a preview doc available shortly

[sberyozkin]

I've enabled the review to get the HTML page - I've just gone again through the whole text, tuned a few things, it looks quite ready to me.

[gastaldi]

LGTM

[sberyozkin]

Hey @gastaldi, thanks for having a look :-). I'll do one more walk-through through the whole demo tomorrow or so (I only reread the text on Fri), as it really must work exactly as described, and will merge once I confirm it works. Cheers

[sberyozkin]

Reacted to a few Lint suggestions

[sberyozkin]

I've updated it more to make sure the integration tests pass when building in JVM and native modes, LGTM overall. I'll now merge it once the build gets green.

[sberyozkin]

Hi @michelle-purcell, we can iterate and keep tuning the doc, thanks very much for the earlier review. I'd just like to try to get it to 3.5.0 and make it visible