Summary of Changes

The event that everyone waiting for :)
This should finally solve an issue everyone hit when need to access to Document at early stage, but onAfterRoute document not available and onAfterDispatch is to late.

PR also add a general Document event class, it introduce classes for 2 events: AfterInitialiseDocumentEvent, BeforeCompileHeadEvent

Note
Before we can merge this PR it would be good to add CMS\ApplicationEvent, and the document event should be a child of it (because technically it is Application event).
Thoughts?

Testing Instructions

Apply #40522 then apply current patch. Solve conflicts.
Add in any System plugin:

public function onAfterInitialiseDocument(Joomla\CMS\Event\Application\AfterInitialiseDocumentEvent $event)
{
    var_dump($event->getDocument()->getTitle());
}

Actual result BEFORE applying this Pull Request

Nothing

Expected result AFTER applying this Pull Request

You should see Dump output.

Link to documentations

Please select:

• Documentation link for docs.joomla.org: https://docs.joomla.org/Plugin/Events#System
• No documentation changes for docs.joomla.org needed
• Pull Request link for manual.joomla.org: IDK
• No documentation changes for manual.joomla.org needed