Problem/Motivation
Field Layout module was in part deprecated by the later addition of Layout Builder module and it never matured out of its experimental stage. It is still in core as an experimental module but it passed its deadline of removal with Drupal 8.5.0-alpha1 quite some time ago. It was not yet removed, but it needs a solution.
Proposed resolution
There are two parts of Field Layout: (1) manage display and (2) manage form display. The manage display part is deprecated and a migration path to Layout Builder is already in place. The manage form display part should be stabilised and moved into Field UI.
The module itself can/should go away.
Remaining tasks
#2844302: Move Field Layout data model and API directly into \Drupal\Core\Entity\EntityDisplayBase
More children needed, identify them.
User interface changes
The manage display UI is replaced with Layout Builder.
API changes
TBD. As an alpha experimental module, no API stability was guaranteed.
Data model changes
TBD.
