MAPG-100 add DB migration for pano id cache

database/migrations/structure/20200603_2135_panoid_cache.sql

@@ -0,0 +1,6 @@
+ALTER TABLE
+  `places`
+ADD
+  `pano_id_cached` varchar(255) NULL DEFAULT NULL,
+ADD
+  `pano_id_cached_timestamp` timestamp NULL DEFAULT NULL;