Integrate block_content with Quick Edit when used as entity reference

Problem/motivation

Block content (Custom block) an be used as target type for entity reference fields. When field formatter is set to "Rendered entity", block content is not rendered as a full entity but as a set of separate fields. As a result, there is no contextual links, no wrapper element and therefore it can not be fully integrated with Quick Edit. The fields of block content entity can not be quickly editable.

Steps to reproduce

• Create a new or use an existing content type
• Add a field of type Reference -> Other
• In "Type of item to reference", select "Custom Block"
• In "Manage Display", set the formatter of the field to "Rendered entity"
• Create a custom block
• Create a node of the content type above
• Reference the custom block just created to the node
• View the node and there is no contextual links for the rendered block content entity

Proposed solution

Remaining tasks

User interface changes

API changes