Conflict between field_learning_path_published and new groups published field

Problem/Motivation

Groups module has made groups publishable - this adds a 'published' base field. See #2873212: Add a status to the group (Publish/Unpublish).

This makes the field_learning_path_published field redundant - we now have two published fields, one can be published, one not, leading to confusing results.

Steps to reproduce

Proposed resolution

Retire field_learning_path_published - will mean a migration of the status to the new groups field, and updating any views.

Remaining tasks

User interface changes

API changes

Data model changes