[Drupal 8.7.x] Replace deprecated 'entity.manager' service by its various successors

Enclosed patch should fix all of them, while striving to be BC not just for callers, but also for extending classes.

Most probably we'll still see one or the other test fail, but Webform tests are too heavy to be run on my local machine.

Oh wow, this looks massive. Let's untangle it one by one, though.

1. Most fails are due to my mistakes in WebformSubmissionViewController::__construct().
2. Apart from that, I have to revert the changes in WebformSubmissionStorage, as the deprecated service has only been removed from ContentEntityStorageBase in Core version 8.7... :/
3. Same with Views' BulkForm.

Most certainly, there's more, but this one should already be significantly better.

Nice. At least D8.8 is green now.

Apart from that, I have to revert the changes in WebformSubmissionStorage, as the deprecated service has only been removed from ContentEntityStorageBase in Core version 8.7... :/

Same for WebformSubmissionViewBuilder and EntityViewBuilder.

Also, more reverts in WebformSubmissionStorage... :/

Same for WebformSubmissionViewController and EntityViewController.
Also, yet another revert in WebformSubmissionStorage.

We should be getting closer, but it might still take one or the other iteration.

Not too many remaining test failures. One more revert, and this patch might test green.

Note however that the PHP 5.6 failures are because webform 5.x is already broken on PHP 5.6.

Found a much better solution for WebformSubmissionStorage.
So if it still tests green, I think we're finally ready for review.

We currently don't really need the $entityFieldManager in WebformSubmissionStorage.
Instead, we may (and should) use SqlContentEntityStorage::getFieldStorageDefinitions(). While it is deprecated as well in D8.7, replacing it by entityFieldManager's getActiveFieldStorageDefinitions() should be a separate issue. I therefore filed #3058902: [Drupal 8.7.x] Replace the deprecated SqlContentEntityStorage::getFieldStorageDefinitions() as a followup.

Also fixed the issue causing the test fails in #7. Are we green again now?

Tests are green, except for PHP 5.6, which is due to #3058899: Unpredictable order of confirmation and notification mails breaks tests on PHP5.

Ready for review.

Some minor fixes.

Fixing another CS issue.

Sorry, but I don't see why it should. At least not in its entirety.
Why do we want to keep using deprecated Core functions without any necessity?

The argument might be that you're not willing to add any BC band-aid code only to remove it in December. That'd be understandable.
A solution might be: fix now, what may be finally fixed; fix in December, whatever we can't fully fix now.

There’s no “resolving the issue completely.” For each Core version, there are new deprecations, as you know.
We may only fix whatever may be fixed for particular Core versions we’re continuing to support.
As of 8.6, there’s more we can fix than we’ve done. #2985600: [Drupal 8.6.x] EntityManager has been split into 11 classes was a nice start, but remains incomplete.

Let me show you in another patch what may be done now without adding any BC band-aid. If you don’t like it, we may still push it to December.