Use Puppet-Datatype Sensitive

• fix some Puppetlint-Complaints, f.e. use Hash $::facts['blubb'] instead of specific global Variables
• let Function mysql::password accept Datatype Sensitive for Password
• let Function mysql_password accept Datatype Sensitive for Password
• add Parameter "sensitive" to Function mysql::password to decide if its Returnvalue should be of Datatype Sensitive
• add Parameter "sensitive" to Function mysql_password to decide if its Returnvalue should be of Datatype Sensitive
• let mysql_user accept Datatype Sensitive for Parameter password_hash
• let mysql::backup::mysqlbackup accept Datatype Sensitive for Parameter $backuppassword
• let mysql::backup::mysqldump accept Datatype Sensitive for Parameter $backuppassword
• let mysql::backup::xtrabackup accept Datatype Sensitive for Parameter $backuppassword
• let mysql::db accept Datatype Sensitive for Parameter $password
• let mysql::server accept Datatype Sensitive for Parameter $root_password
• let mysql::server::backup accept Datatype Sensitive for Parameter $backuppassword
• let mysql::server::monitor accept Datatype Sensitive for Parameter $mysql_monitor_password
• let mysql::server::root_password accept Datatype Sensitive for $root_password
• refactor Logic for unset Password for mysql::server::root_password