* Fix nil checking on typed interface - Partially resoles #17596 - Resolves SA4023 errors. - Ensure correctly that typed interface are nil. * Remove unnecessary code `NewBleveIndexer` will never return nil, even on errors. * Patch `NewBleveIndexer` * Fix low-level functions * Remove deadcode * Fix GetSession * Close Elastic search when err isn't nil * Update elastic_search.go Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com> Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>