Move state management to the Entity API?

Notes:

• ApiController::saveInstanceAsPreset() doesn't save third party settings (UI style)s, but it doesn't seem related to the current work

MR open. Work in progress.

Notes:

• ApiController::saveInstanceAsPreset() doesn't save third party settings (UI style)s, but it doesn't seem related to the current work
• SseApiController has not been properly tested

Manual tests failed:

• Logs are not saved anymore
• After deleting an instance, the "already saved" status is lost
• Entity display overrides are saved in the entity displays config instances

Unit tests failed:

• Drupal\Tests\display_builder_page_layout\Kernel\PageLayoutEntityTest::testPageLayoutEntityCrud
• Drupal\Tests\display_builder_page_layout\Kernel\PageLayoutEntityTest::testPageLayoutFormBuild
• Drupal\Tests\display_builder_page_layout\Kernel\PageLayoutEntityTest::testPageLayoutEntityEdit

Playwright tests failed:

• From fixture: timeout
• Views Display Builder: expect(page.getByRole('dialog')).toBeHidden()

pdureau → credited grimreaper → .