Is there a ready-made open source solution for blocks with content?

Question

css

I am making an admin panel for the quest engine (LAMP). The client must add jobs there.
Previously, they uploaded all content through one WYSIWYG editor (Ckeditor). But now it became clear to me that it is better to implement the addition in separate blocks (to choose from: text, image, sound, video, etc.). And so that after adding the blocks you can move, change their order if necessary.

I started writing my bike, and then I thought: maybe such a solution already exists? Gihab search yielded no results. Can you tell me where to dig?