MAR-218: Force handler execution during testing for consistency:

- Otherwise it can easily happen that some handlers never run, leaving
the machine in inconsistent state until they are run by hand.

MAR-218: Drop linting definitions from Molecule configuratin files:

- Molecule no longer natively supports running linters.
- Disable the Ansible Galaxy dependency installation (none of the
roles utilise this).

MAR-192: Added support for Debian 12 Bookworm to database_server role:

- Newer versions of MariaDB are planning on making the utf8 become a
default alias for utf8mb4. Stick to utf8mb3 currently for
compatibility purposes.

MAR-189: Disable use of KVM paravirtualisation provider with Vagrant/VirtualBox:

- The VMs seem to randomly hang when the (KVM) clock source gets
initialised right after getting past the bootloader. Helps run the
tests in a way more reliable way.
- Should be removed if upgrading to latest kernel/VirtualBox versions
helps.

MAR-189: Remove deprecation-related tasks and tests for database_server role:

- These were relevant in some older versions of Debian and needed
during upgrades from versions that still employed passwords for
system logins/tasks.

MAR-151: Added support for Debian 10 Buster to database_server role:

- Updated role reference documentaiton.
- Updated role meta information.
- Updated tests.
- Deploy MariaDB client login configuration prior to setting-up
users/passwords for deprecated feature testing to avoid errors when
password gets changed in the middle of a task loop.

MAR-168: Introduce additional machine in database_server tests for testing deprecated features:

- Updated Molecule configuration, defining an additional machine.
- Set-up the new machine with pre-installed MariaDB server instance,
root login with password, and separate Debian system maintenance
user.
- Set-up configuration files for root and Debian system maintenance
user login.
- Run the default set of tests on the deprecated machine group.

MAR-148: Disable Ansible's default of enforcing group names without dashes through Molecule configuration files:

The following links might be a useful read:

- https://github.com/ansible/ansible/issues/56930 (issues relaetd to
lack of docs, but many complaints and explanations within)
- https://groups.google.com/forum/#!topic/ansible-devel/bjAcM9ferIw

MAR-132: Added support for Debian 9 (Stretch) to database_server role:

- Updated Molecule test configuration to include Debian 9 Stretch in
test matrix.
- Updated tests related to UTF-8 configuration (differences between
Debian 8 and 9).
- Deploy UTF-8 configuration in alternate locations depending on what
distro is being used.
- Force set-up of root password on Debian Stretch (default is to use
the unix_socket authentication).

MAR-128: Upgraded tests for database_server role:

- Switch to new Molecule configuration.
- Updated set-up playbook to use become: yes.
- Moved some preparatory steps outside of the main playbook (eases
idempotence tests).
- Updated tests to reference the yml inventory file.
- Updated tests to use new fixture (host instead of individual ones).