Check returns values added in #3283794

There were 92 changed files.

64 files were changed to add return []; to empty getNormalizedPostEntity() and empty getPostDocument() in various tests to match the relevant interface.

4 migrate_drupal_ui files were changed to add return []; to empty methods to match the definition of the method defined in the base class.

2 migration test bases classes changed to conform to relevant interface. Including add the throwing of a RuntimeException for methods not implemented.
\Drupal\Tests\migrate_drupal\Unit\source\TestDrupalSqlBase::query now throws a RuntimeException not implemented

1 file changed to fix switch statement
1 file incorrectly changed for recursiveKSort
1 file changed to removed useless return statements from assert helper methods
AssertContentTraitchanged to return void for assert helper methods
EntityResolverManagerTest, FormStateTest so test class matches FormInterface
FieldDefinitionTest add a throw for the error case

These are require a bit more thought, not low hanging fruit.

These were fixed to match the base method @return. However, the base method returns NULL but the doc is '@return string'.

• \Drupal\Tests\jsonapi\Functional\FileUploadTest::getExpectedUnauthorizedAccessMessage
• \Drupal\Tests\jsonapi\Functional\NodeTest::getExpectedUnauthorizedAccessMessage
• \Drupal\Tests\jsonapi\Functional\RestJsonApiUnsupported::getExpectedUnauthorizedAccessMessage
• \Drupal\Tests\user\Functional\UserRegistrationRestTest::getExpectedUnauthorizedAccessMessage

These changed to return new CacheableMetadata(); instead of void.

• \Drupal\Tests\jsonapi\Functional\FileUploadTest::getExpectedUnauthorizedAccessCacheability.
• \Drupal\Tests\jsonapi\Functional\NodeTest::getExpectedUnauthorizedAccessMessage
• \Drupal\Tests\jsonapi\Functional\RestJsonApiUnsupported::getExpectedUnauthorizedAccessCacheability
• \Drupal\Tests\layout_builder\Functional\Rest\LayoutRestTestBase::getExpectedUnauthorizedAccessCacheability
• \Drupal\Tests\rest\Functional\FileUploadResourceTestBase::getExpectedUnauthorizedAccessCacheability
• \Drupal\Tests\user\Functional\UserRegistrationRestTest::getExpectedUnauthorizedAccessCacheability

These are still todo

• core/modules/comment/tests/src/Functional/CommentNonNodeTest.php
• core/modules/layout_builder/tests/modules/layout_builder_test/src/Plugin/SectionStorage/TestStateBasedSectionStorage.php
• core/modules/migrate/tests/src/Unit/TestMigrateExecutable.php
• core/modules/system/tests/src/Functional/Form/StubForm.php
• core/modules/system/tests/src/Unit/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php
• core/tests/Drupal/Tests/Core/Image/ImageTest.php
• core/tests/Drupal/Tests/Core/Plugin/LazyPluginCollectionTestBase.php