Follow-up for #3446722: `side_by_side` + `accordion` (+ maybe `text`) components

Overview

#3446722: Introduce an example set of representative SDC components; transition from "component list" to "component tree" landed all MRs created by @ctrlADel at DrupalCon Portland in May 2024 (and which he discussed with @lauriii), except 3:

1. side_by_side — removal commit: https://git.drupalcode.org/project/experience_builder/-/merge_requests/2... — rationale quoted from the original issue:
   

   Side by Side
   This component covers most of the features any given component will need. It reuses a fully slotted two column component, has 2 props of it's own, embeds 3 other SDC components, and includes a restricted drop zone for media items.
   

2. accordion — removal commit: https://git.drupalcode.org/project/experience_builder/-/merge_requests/2... — rationale quoted from the original issue:
   

   Accordion
   This component has a slot for the header that embeds the heading and text components, a slot to be used as a dropzone for the accordion items where multiple elements will need to be dropped. The items themselves will also have an unrestricted dropzone for the accordion content.
   

3. text — removal commit: https://git.drupalcode.org/project/experience_builder/-/merge_requests/2... — see #3446722-68: Introduce an example set of representative SDC components; transition from "component list" to "component tree" for the clarifications this needs.

Proposed resolution

TBD

User interface changes

TBD