Move code indexer related code to a new package (#9191)

* move code indexer related code to a new package

* fix lint

* fix tests

* fix fmt

* GetMaxID support interface parameter

models/repo.go

@@ -1112,10 +1112,6 @@ func MigrateRepositoryGitData(doer, u *User, repo *Repository, opts api.MigrateR
 		repo, err = CleanUpMigrateInfo(repo)
 	}
 
-	if err != nil && !repo.IsEmpty {
-		UpdateRepoIndexer(repo)
-	}
-
 	return repo, err
 }