Issue #3399370 by mstrelan: Remove @file annotation from test classes

...nfig_translation/tests/src/Unit/ConfigNamesMapperTest.php

...odules/field/tests/src/Unit/FieldConfigEntityUnitTest.php

...field/tests/src/Unit/FieldStorageConfigEntityUnitTest.php

core/modules/migrate/tests/src/Kernel/SqlBaseTest.php

core/modules/migrate/tests/src/Unit/MigrateSourceTest.php

core/modules/migrate/tests/src/Unit/MigrationTest.php

...Unit/Plugin/migrate/destination/EntityContentBaseTest.php

...ts/src/Unit/Plugin/migrate/destination/EntityTestBase.php

core/modules/migrate/tests/src/Unit/SqlBaseTest.php

...migrate/tests/src/Unit/destination/EntityRevisionTest.php

...ts/src/Unit/destination/PerComponentEntityDisplayTest.php

...rc/Unit/destination/PerComponentEntityFormDisplayTest.php

core/modules/migrate/tests/src/Unit/process/ConcatTest.php

...te_drupal/tests/src/Unit/source/d6/Drupal6SqlBaseTest.php

...odules/search/tests/src/Unit/SearchPageRepositoryTest.php

...n/tests/src/Unit/Normalizer/ComplexDataNormalizerTest.php

...lization/tests/src/Unit/Normalizer/NormalizerBaseTest.php

...les/system/tests/src/Kernel/Scripts/DbCommandBaseTest.php

...s/src/Unit/Breadcrumbs/PathBasedBreadcrumbBuilderTest.php

core/modules/user/tests/src/Unit/PermissionHandlerTest.php