feat(core): handle previous deleted attributes when creating a new one

search-service/src/main/kotlin/com/egm/stellio/search/entity/service/EntityAttributeService.kt

@@ -104,6 +104,12 @@ class EntityAttributeService(
             VALUES 
                 (:id, :entity_id, :attribute_name, :attribute_type, :attribute_value_type, :created_at, :dataset_id, 
                     :payload)
+            ON CONFLICT (entity_id, attribute_name, dataset_id)
+                DO UPDATE SET deleted_at = null,
+                    attribute_type = :attribute_type,
+                    attribute_value_type = :attribute_value_type,
+                    created_at = :created_at,
+                    payload = :payload
             """.trimIndent()
         )
             .bind("id", attribute.id)

search-service/src/main/resources/db/migration/V0_44__add_deleted_at_temporal_property.sql

@@ -1,5 +1,13 @@
 ALTER TABLE temporal_entity_attribute
-ADD COLUMN deleted_at timestamp with time zone;
+    ADD COLUMN deleted_at timestamp with time zone;
 
 ALTER TABLE entity_payload
-ADD COLUMN deleted_at timestamp with time zone;
+    ADD COLUMN deleted_at timestamp with time zone;
+
+DROP INDEX IF EXISTS temporal_entity_attribute_null_datasetid_uniqueness;
+
+ALTER TABLE temporal_entity_attribute
+    DROP CONSTRAINT temporal_entity_attribute_uniqueness;
+
+ALTER TABLE temporal_entity_attribute
+    ADD CONSTRAINT temporal_entity_attribute_uniqueness UNIQUE NULLS NOT DISTINCT (entity_id, attribute_name, dataset_id);