feat: enable auto migration based on resource count (#115619)

* feat(unified): migration at startup based on resource count

-- draft

* feat: introduce auto migration enablement for dashboards & folders

* feat: enable auto migration based on threshold

* fix: improve

* fix: pass in the auto migrate per migration definition

* fix: minor

* fix: only use one options

* fix: test

* fix: test

* fix: tests

* fix: simplify configs

* chore: rename

* fix: add integration test

* fix: add integration test

* fix: integration tests

* chore: add comments

* fix: address comment

* fix: address comments

* fix: test and auto migration flow

* fix: test

---------

Co-authored-by: Rafael Paulovic <rafael.paulovic@grafana.com>

pkg/registry/apis/dashboard/legacy/sql_dashboards.go

@@ -224,7 +224,7 @@ func (a *dashboardSqlAccess) CountResources(ctx context.Context, opts MigrateOpt
 			case "folder.grafana.app/folders":
 				summary := &resourcepb.BulkResponse_Summary{}
 				summary.Group = folders.GROUP
-				summary.Group = folders.RESOURCE
+				summary.Resource = folders.RESOURCE
 				_, err = sess.SQL("SELECT COUNT(*) FROM "+sql.Table("dashboard")+
 					" WHERE is_folder=TRUE AND org_id=?", orgId).Get(&summary.Count)
 				rsp.Summary = append(rsp.Summary, summary)