MAR-192: Drop rsyslog/logrotate configuration for ldap_server role under Debian 12 Bookworm:

- Default installations of Debian 12 Bookworm no longer come with
rsyslog pre-installed (and it is considered to be deprecated as
default system logger under Debian 12 Bookworm).

MAR-165: Deploy Diffie-Helman parameters for LDAP server in the ldap_server role:

- Not relevant for Debian Strech because of a bug in the OpenLDAP
version it ships with.
- This should allow use of DHE ciphers with LDAP server.
- Generated DH parameters only help pick one of the parameters from
RFC-7919 (based on the size of generated ones).
- Make the cipher test lists distro-specific due to differences
between supported algorithms in respective GnuTLS versions.

MAR-150: Use fixtures for X.509 artefacts in the ldap_server role:

- Removed the statically generated artefacts.
- Generate X.509 artefacts for tests using Gimmecert.
- Updated paths to point to generated artefacts.
- Introduced cleanup playbook for removing generated artefacts.

MAR-162: Deduplicate TLS private key/certificate tests for LDAP server role:

- Rename the key/certificate files to match the Ansible inventory
name.
- Move the tests into test_default.py.
- Change the key/certificate extensions to be more descriptie.

MAR-149: Switch to using File.content_string instead of File.content in tests for all roles:

- The .content variant returns contents as bytes, while the
content_string returns a string (which is what is wanted in
practically all cases).

MAR-152: Revert path change for LDAP server unix socket test:

By default OpenLDAP server opens unix socket to listen on at
/var/run/slapd/ldapi, and this is what netstat will list as a
path (with e.g. netstat -xl).

Testinfra in turn relies on netstat output, and therefore a canonical
path has to be used. This might change in next release (Buster),
though - since Debian is trying to transition all applications to use
/run instead of /var/run.

MAR-129: Updated ldap_server role for new Molecule and Ansible:

- Fixed syntax warnings.
- Moved test playbook variables into group_vars.
- Optimised the invocation of test playbook.
- Remove the 'ss' utility from test machines in order to properly test
the unix sockets.
- Fixed how the hosts are being referenced in tests.

MAR-128: Upgraded tests for ldap_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).
- Fixed some linting issues.
- Use localhost as backup client server name. This should make it
simpler in future to cover more platforms.
- Set-up the /etc/hosts for tests with correct entries (primarily
aliases towards localhost to make it less important what the
hostname is).
- Renamed private key/certificate files for parameters-mandatory
server since server got renamed as well.
- Updated IP addresses used for testing to make it easier to test new
platforms in the future.
- Use inventory_hostname-based parameterisation of tests where
appropriate. Currently hard-coded value for this because
host.ansible.get_variables() produces errors.