Set [mariadb] configurable to allow MariaDB multi-instance

[steph-perez]

Hello,
In the template file templates/etc_my.cnf.d_server.cnf.j2 the name [mariadb] is hard-coded.
Is it possible to make this name dynamic?
For example we would like to have [mariadb.inst1] in order to start it with systemctl start mariadb@inst1.service
Thank you.