2831349 : Check usage in the revisions on demand.

The solution is to use config form and entity_query method.

config/schema/entity_reference_integrity.schema.yml

+# Schema for the configuration files of the Entity Reference Integrity module.
+entity_reference_integrity.settings:
+  type: config_object
+  label: 'Entity Reference Integrity settings'
+  mapping:
+    example:
+      type: string
+      label: 'Example'