Component groups for code components

This seems very important for usability? Bumping priority and tagging.

This also seems not blocked anymore?

This feels almost like a sensible next step after 📌 [Needs design] Library confusingly lists SDC-sourced and Block-sourced Components together Active , but AFAICT it's not limited to code components — it applies to all \Drupal\experience_builder\Entity\PrimaryComponents? 🤔

So per the logic in \Drupal\experience_builder\Entity\Component::computeUiLibrary(), it will apply to both theme-provided SDCs (module-provided ones end up under either dynamic components or extension components) and XB's code components.

Applied #5 to the questions in the issue summary — please review 🙏

I think #5 + #6 are the needed update now that this is actually actionable :D