Added feeds config for data migration

config/field.storage.oc_case.feeds_item.yml

@@ -0,0 +1,20 @@
+uuid: c1326650-f421-4ede-81f3-250840ccf1b9
+langcode: en
+status: true
+dependencies:
+  module:
+    - feeds
+    - opencase_cases
+id: oc_case.feeds_item
+field_name: feeds_item
+entity_type: oc_case
+type: feeds_item
+settings:
+  target_type: feeds_feed
+module: feeds
+locked: false
+cardinality: 1
+translatable: false
+indexes: {  }
+persist_with_no_fields: false
+custom_storage: false