[meta] Tasks to deprecate the Field Layout module

Problem/Motivation

Track the steps needed to deprecate extension Field Layout. See Remove a core module and move it to a contributed project of the deprecation policy.

The removal of extension Field Layout was approved in #3007167: [policy] Deprecate field_layout module and move it to contrib.

Remaining tasks

1. Begin finding someone to maintain the contrib version of the extension.
   @andypost has agreed to maintain the project contrib project exits.
2. Move integrations implemented by other modules to the extension.
   Create child issues or child meta issues, as needed, to address the following points. Not all points will apply to all extensions.
   • Move non-migration tests to the extension.
   • Move Help Topics to the extension.
   • Remove references to the extension from database dumps. - Not used in the db dumps.
3. Do a thorough search of core for any remaining references to the extension. If references are found, outside of the extension, then create issues to remove the references.
4. Create the contrib project with a stable release, before the alpha version of the major release. Follow the process in Create the contrib project with a stable release for creating the sub tree split.
5. Deprecate the core extension. #3517719: Deprecate the Field Layout module.
6. #3567857: Ensure that Field Layout does not get special core treatment