HTK - added verify_databases_backup_in_directory function that is
going to be defined inside mariadb/postgresql/etcd charts.
Mariadb chart - added verify_databases_backup_archives function
implementation.
Added mariadb-verify container to mariadb-backup cronjob to run
verification process.
Added remove backup verification pocess - comparition of local and remote file md5 hashes.
PostgreSQL chart - added empty implementation of verify_databases_backup_archives() function. This is a subject for future realization.
Change-Id: I361cdb92c66b0b27539997d697adfd1e93c9a29d
5c4056ad34