Add useful message on providers page when no provider enabled

I raised the same issue over in https://www.drupal.org/project/ai/issues/3498757#comment-15939611 🐛 Installation/configuration resilience (ai_translate) Active , so I'm in a position to test this patch later today.

I believe it needs a bit more than what is done here because by removing the check for existing providers we'll see the message "You do not have any administrative items." It's still better than Access denied though.

There's some related chat over at https://www.drupal.org/project/ai/issues/3499412#comment-15944839 📌 Make selection of AI Provider clearer on module homepage Active too.

I can't see any changes in your fork, so I've not been able to install and test this. I'd very much like to see the Access Denied error resolved.

I've made some text change suggestions on that other issue 📌 Make selection of AI Provider clearer on module homepage Active , which just adds a new Warning message and doesn't address the Access Denied error.

If those suggestions are picked up, then perhaps your new message could read:

There are no AI providers available. Choose at least one AI provider module from those listed on the AI module homepage, add to your project, install and configure it here. Then update the AI Settings.

With links to:

1. "AI module homepage" to https://www.drupal.org/project/ai →
2. "AI Settings" to /admin/config/ai/settings

Code to resolve this issue appears to be being added to https://www.drupal.org/project/ai/issues/3498893 🐛 Default option for Media type can be wrong if not selected in Ai Automator Advanced settings Active so to avoid confusion, I'm going to close this as a duplicate.

@mrdalesmith that's a different issue on the page before you reach this one. I tested and made comments on that yesterday. This issue is not resolved by that solution. This issue should be re-opened.