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: 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: Switch to using PyMySQL module for database and database_server role:

- Explicitly specify the path to MariaDB unix socket to enforce unix
socket authentication.

MAR-163: Reformat multiple skip-QA directives and remove some unnecessary ones:

- Update codes used to identify the disabled QA checks.
- Switch to using new syntax that disables only a specific QA check
instead of all of them on a single task.
- Drop disabling QA checks related to octal file permissions (this was
most likely bug in older versions of ansible-lint).

MAR-168: Minor fixes for the debian_server role:

- Drop the workaround for enabling the mysql service (Debian Stretch
and upwards use pure systemd unit file).
- Improved name of one of the tasks.

MAR-168: Drop the Debian system maintenance user if present:

- Drop the user itself from the MySQL database.
- Update the Debian system maintenance configuration file if root is
not specified as the user within.
- Updated tests.
- Updated release notes.
- Updated role reference documentation.

MAR-168: Drop the user of passwords for the root MySQL account:

- Rely on unix_socket authentication plugin instead.
- Updated role reference documentation.
- Updated tests.

MAR-148: Fixing linting errors:

- Do not compare against booleans when value is already boolean in
"when" conditions.
- Use pipefail in conjunction with setting the shell to Bash when
extracting the backup encryption key IDs.
- Do not compare variables to empty strings in "when" conditions. This
change currently works only for complex variables (stuff can break
badly in case of simple variables in current default Ansible
configuration).
- Fix missing space in one of Jinja2 templates.

MAR-134: Fix Ansible warning about use of apt and with_items:

- The apt module can accept list of names already, and with_items is
considered to be deprecated in this regard (otherwise it would
end-up running one apt command per item).
- Changed multiple roles where apt was used together along with_items.

MAR-135: Switch to using run_handlers instead of handlers as variable:

- Updated all roles to now depend on run_handlers being set to True in
order to force execution of handlers.

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-114: Updated task syntax for database roles:

- Updated database and database_server roles.
- Added and removed quoting where it makes sense.
- Switched to using expanded syntax (instead of one-liners).

MAR-24: Implemented tests for 'database_server' role:

- Added Molecule configuration for single platform and instance.
- Added test playbook that deploys database_server role for testing.
- Fixed mode setting by appending leading zero.
- Ignore task that immediatelly restarts MariaDB database server.
- Implemented tests for the role covering full functionality.