Not sure if md5 hex (32signs) is ok, (on attachment init is 24 signs, but this two are hardcoded - probably gonna be deleted anyway in later steps of project)
Multer working great, saving files in database - tested on Postman
Adding two files with same name generating diffrent fileNameHashes, both are working( in my opinion it's much better then being allow to add 1 hash - 1 name)