Issue #2571533 by damiankloip, yched: Allow setting custom storage on FieldStorageConfig

...ntent/config/install/field.storage.block_content.body.yml

...ent/config/install/field.storage.comment.comment_body.yml

core/modules/field/config/schema/field.schema.yml

core/modules/field/field.post_update.php

core/modules/field/src/Entity/FieldStorageConfig.php

core/modules/field/src/Tests/FieldCrudTest.php

...g/install/field.storage.entity_test.field_test_import.yml

...install/field.storage.entity_test.field_test_import_2.yml

...g/field.storage.entity_test.field_test_import_staging.yml

...field.storage.entity_test.field_test_import_staging_2.yml

...forum/config/install/field.storage.node.comment_forum.yml

...rum/config/install/field.storage.node.taxonomy_forums.yml

...g/install/field.storage.taxonomy_term.forum_container.yml

core/modules/node/config/install/field.storage.node.body.yml

...config/install/field.storage.node.field_options_float.yml

.../modules/system/src/Tests/Update/UpdatePostUpdateTest.php

...es/standard/config/install/field.storage.node.comment.yml

...tandard/config/install/field.storage.node.field_image.yml

...standard/config/install/field.storage.node.field_tags.yml

...andard/config/install/field.storage.user.user_picture.yml