[META] Block attachments are not loaded

Problem/Motivation

• 🐛 Some blocks are not rendering the css correctly Active
• 🐛 Custom js library doesn't work with an ajax block Active

Steps to reproduce

Proposed resolution

Block attachments need to be respected and also loaded in AJAX.

Maybe CommandWithAttachedAssetsInterface can help?

Remaining tasks

User interface changes

API changes

Data model changes