Fix group_fields region after compose_tabs layout is disabled
When we uninstall field_layout and compose, the config settings for
third_party_settings:
field_group:
group_group_name:
region: fields
remain assigned to the 'fields' region. When we view the Form mode for the entity, these groups end up in the 'hidden' region, and there are PHP errors from field_ui
(because the child fields reference a parent that doesn't exist?).
This change moves any field_groups that are not already hidden into the default content region.
Since this uninstall hook already provides me the resulting yml that I want, I only need to commit my yml to move forward.
But if you want to improve this or need it for later, I figured an MR was the best way to collaborate with you on this issue.
I could not determine which part of the uninstall / entity_display save process was making the non-group fields reassign to the correct default region; If there is a more "core" way of doing this, I'd love to know :)