Problem/Motivation
This is a followup issue for #1875252: [META] Make the block plugin UI shippable. In that thread, discussion centered around making the block's UI "shippable", due to multiple UX issues.
Proposed resolution
An improved Block UI was proposed in #67 on the issue above. This UI merges the two existing block management pages into a single UI.
The main changes are that the two block screens are merged together, and the interface for adding a block is now a revealable accordion on the left side of the block placement interface.
This UI is outlined in https://projects.invisionapp.com/share/6AESEWGY#/screens/7279850.
Remaining tasks
- Rework the theme block listing at admin/structure/block to match that provided
- Remove the page/UI for adding blocks known as "Place blocks", at admin/structure/block/list/block_plugin_ui%3Atheme-name/add
- Rework the interface for adding custom blocks to remove Region-specific settings
- Add the collapsible block list to the updated listing page
- Add the modal interface for adding a block to a region
Related, with further UX implications: