Empty layout sections get rendered

Adding a patch for the 10.1.x branch.

Fixed a couple more tests

Thank you for this! See this often with clients who aren’t great with layout builder.

Still seem to be some test failures however. Definitely keeping this on the radar

@tim.plunkett added a condition so the sections do build in layout builder side.

Thoughts?

Thanks. Also seemed to cause some additional test failures that I'll look at.

So this additional checks seems to be the best way to cover all scenarios.

When adding a section _layout_builder isn't there.

Tried _admin_route but that caused test failures also.

Fixing merge (using rebase) to allow me to review better

@tim.plunkett wonder if you had a chance to review?

I'll have to re-review, the change to checking for `layout_builder_tempstore` is tricky

Tried this out on a local project and I use drush search-api-index

But I get this error

> [error] Error while trying to render item entity:node/48:en with view mode full for search index tetra_tech: Call to a member function getOption() on null in Drupal\Core\Layout\LayoutDefault->build() (line 70 of /var/www/html/webroot/core/lib/Drupal/Core/Layout/LayoutDefault.php).

So seems all scenarios aren't caught.

Adding a patch for the 10.2.x branch

Rerolled the patch for the 10.3.1 branch