MAR-192: Switch to using go-sendxmpp where possible for testing XMPP server role:

- The sendxmpp in Debian 12 Bookworm is quite broken at this point,
and go-sendxmpp is somewhat close in terms of interface etc.
- Fix a number of tests related to sending messages.

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

- Some of the tests are still failing, namely the ones centered around
the sendxmpp tool (which seems completely broken at this point in
Debian 12 Bookworm)

MAR-192: Align IP ranges used for testing VMs in the xmpp_sever role:

- Use two consecutive ranges for Debian 11 Bullseye like in
mail_server.

MAR-189: Added support for Debian 11 Bullseye to xmpp_server role:

- Roll-out LDAP client configuration since Bullseye does not come with
a stock one at /etc/ldap/ldap.conf that sets the trust anchor
correctly for validating LDAP server certificates.
- Drop the backports pinning in case of Bullseye (for now let's try to
keep the Buster and Bullseye at same versions for simplicity).
- Drop installation of Python apt bindings (no longer used).
- Tests for Buster and Bullseye need to be split-up a bit due to some
differences around backports etc.

MAR-189: Dropped deprecation-related tasks and tests for xmpp_server role:

- Migration from Prosody project repositories should have been done
already as part of the 7.0.1 release.
- Simplifies the code a bit.
- Drop leftover deprecated library plugin path.

MAR-186: Reorder the deprecation tasks for xmpp_server role to make the runs reliable:

- Deprecated apt repository really needs to be removed first in case
it has an unresolvable URL (so the backports repository cache update
would trigger correctly).
- Use the file removal for Prosody repository as well to make sure the
file is dropped.

MAR-181: Use Debian-provided Prosody package instead of project repository:

- Upstream repository has a tendency to drop support for older Debian
releases, and to completely wipe old version repositories.
- It should be way less hassle to simply start using the
Debian-provided packages instead.
- Introduces deprecation tests to check if the role will also clean-up
the non-Debian packages.

MAR-181: Added workaround for Debian Buster tests:

- The upstream has dropped the repositories for Debian Buster.
- Depend on alternative repository set-up on Majic servers.
- Not a permanent fix, but at least it keeps the tests going.

MAR-181: Drop support for Debian 9 Stretch from the xmpp_server role:

- Switch to using IPs from VirtualBox default allowed host-only
network subnets.
- Drop Stretch-specific workarounds, code, and tests.

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

- Updated role reference documentaiton.
- Updated role meta information.
- Updated tests.
- Enable lower-level TLS protocols (1.0/1.1) in global OpenSSL
configuration file on Buster in order to be able to test the
xmpp_server_tls_protocol parameter (otherwise Prosody completely
refuses to use them even if listed in its configuration).
- Move stretch-specific tests into its own file (for backported
lua-ldap library), and run them on Debian 9 Stretch machines only.

MAR-164: Fix Prosody TLS configuration in xmpp_server role:

- Added warning to role reference documentation about what DNS names
need to be included in the subject alternative name of issued
certificate used for Prosody.
- Added crontab with script that validates the certificate on daily
basis.
- Updated tests to include the proxy.DOMAIN and conference.DOMAIN DNS
names in subject alternative name for generated test certificates.
- Added and updated tests that cover new functionality.
- Fixed the Prosody TLS configuration to have common parameters
specified in general section, and any kind of overrides (mainly the
ciphers) in more specific sections.
- Updated release notes.

MAR-171: Make the xmpp_domains parameter mandatory:

- Updated release notes.
- Updated role reference documentation.
- Dropped the default value for parameter from the xmpp_server role.
- Updated tests.

MAR-164: Harden the c2s TLS configuration for the XMPP server role:

- Updated the xmpp_server role.
- Added (optional) xmpp_server_tls_protocol and
xmpp_server_tls_ciphers parameters for specifying the desired
TLS protocol version and ciphers for the c2s connections.
- Updated XMPP server configuration to introduce separate TLS
configuration for the s2s and c2s (legacy included) connections.
- Drop support for Prosody 0.9 since it is not possible to have
separate TLS configuration for c2s and s2s connections.
- Updated role reference documentation.

MAR-150: Use fixtures for X.509 artefacts in the xmpp_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-132: Added support to xmpp_server role for Debian 9 (Stretch):

- Updated tests to include Debian 9 in testing. Existing private keys
are reused where possible (since most of the naming is identical
between the machines with jessie/stretch).
- Updated invocation of sendxmpp in tests as workaround for
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=854210.
- Updated testing of imported keys to accomodate differences between
gpg/gpg2 (used by apt-key in Jessie/Stretch).

MAR-132: LDAP-related fixes to xmpp_server role tests:

- Do not create LDAP accounts through the ldap_entries parameter of
ldap_server, use the ldap_entry and ldap_attr modules directly.

MAR-129: Updated xmpp_server role for Ansible 2.5.x and new Molecule:

- Include top-level lint configuration in test configuration.
- Fixed linting errors.
- Moved test playbook variables into group_vars and host_vars.
- Fixed deprecation warnings from Ansible.
- Updated how hosts are referenced within tests.

MAR-128: Upgraded tests for xmpp_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).
- Switched to extracting hostname instead of hard-coding it in a
couple of tests.
- Renamed hosts to include the Debian version.
- Updated names for some of the test data to cater to change in host
names.
- Switched to using more robust task for populating /etc/hosts.