Add Event Triggers to content Filter

[PxaMMaxP]

In this merge I add important event triggers to improve the consistency in the functionality of PicoCMS. Previously, the onContentPrepared and onContentParsed events were only triggered when a page was called directly.

This limitation led to problems with plugins that rely on these events, especially if the content was processed via the internal Twig filter content. The added event triggers in the content filter ensure that all plugins involved in content creation work smoothly even when the content filter is used.

This change ensures broader and more reliable plugin compatibility within PicoCMS.

[PhrozenByte]

Thank you for your PR! 👍

I assume you accidentally selected the wrong branch to merge, you probably rather meant to select your content-filter-trigger-events branch instead of your pico-3.0 branch. You might wanna open another PR.

Besides, I'm afraid that we can't merge it the way it is, because the onContentPrepared and onContentParsed events were designed to only fire for the requested page, not for other pages as well. This will likely break a lot of plugins, they just don't expect that. For other pages we have the onSinglePageLoading, onSinglePageContent, and onSinglePageLoaded events. Since we indeed don't have events that fire before and after Markdown processing, we could indeed add such new events, just with a different name.

We'd have to let PicoDeprecated know about these new events as well.

[PxaMMaxP]

Heyy,

thanks for your detailed explanations, and sorry for the confusion with the wrong branch.

About the change of the content-filter-trigger-events branch:
My problem was that when I rendered the content of several pages with the content-filter on one page, the corresponding plugins were not applied to that content.

In my specific case, it was the targetBlank plugin. Links were not changed accordingly on the content-->content-filter-->output path.

I noticed that there was no note (issue..) about this and it should have made me suspicious.

I'll close the pull request and take another close look at the whole thing.