#3451750 Numeric to entity target id (alternative approach)

Issue #3451750 This MR is an alternative to !144 (closed) rather than than revert that work. Keep both to allow different approaches to be tested.

config/install/views.view.scheduler_scheduled_content.yml

@@ -1105,7 +1105,8 @@ display:
           not: false
           entity_type: node
           entity_field: uid
-          plugin_id: numeric
+          plugin_id: entity_target_id
+          target_entity_type_id: user
       empty:
         area_text_custom:
           id: area_text_custom