Search: Add search index configuration options (#55525)

* Search: externalize config

* Search: update config descriptions

* Search: fix value

* Search: fix

* update

* Search: revert config values

* Search: rename copy/paste

* Search: fix tests

pkg/services/searchV2/service.go

@@ -81,12 +81,13 @@ func ProvideService(cfg *setting.Cfg, sql *sqlstore.SQLStore, entityEventStore s
 			ac:  ac,
 		},
 		dashboardIndex: newSearchIndex(
-			newSQLDashboardLoader(sql),
+			newSQLDashboardLoader(sql, cfg.Search),
 			entityEventStore,
 			extender.GetDocumentExtender(),
 			newFolderIDLookup(sql),
 			tracer,
 			features,
+			cfg.Search,
 		),
 		logger:     log.New("searchV2"),
 		extender:   extender,