Manage display "Default" has inconsistent markup & two paths in admin UI

Akhil Babu → made their first commit to this issue’s fork.

Patch #28 changes the url of "manage display" tab from ...../display to ..../display/default for all entities.
Accessing the previous manage display url (eg: admin/structure/types/manage/article/display ) will result in 404. Do we really need to update the url to fix this problem. Couldn't we use 'view_mode_name' => 'default' as the default value for entity.entity_view_display.{$entity_type_id}.view_mode route?

I am not sure if it's the correct way to fix this issue. So adding that change alone in a separate MR.

Tested MR #35 in drupal 11.x-dev.
it's resolved issue.

Steps to reproduce:

1.Go to /admin/structure/types/manage/article/display
2.Notice that the Default tab is highlighted as active
3.Now visit /admin/structure/types/manage/article/display/default
4.Apply patch.

After Patch

Before patch

pipeline failed moving to NW.

pooja saraah → made their first commit to this issue’s fork.