Move roles/matrix* to roles/custom/matrix*

This paves the way for installing other roles into `roles/galaxy` using `ansible-galaxy`,
similar to how it's done in:

- https://github.com/spantaleev/gitea-docker-ansible-deploy
- https://github.com/spantaleev/nextcloud-docker-ansible-deploy

In the near future, we'll be removing a lot of the shared role code from here
and using upstream roles for it. Some of the core `matrix-*` roles have
already been extracted out into other reusable roles:

- https://github.com/devture/com.devture.ansible.role.postgres
- https://github.com/devture/com.devture.ansible.role.systemd_docker_base
- https://github.com/devture/com.devture.ansible.role.timesync
- https://github.com/devture/com.devture.ansible.role.vars_preserver
- https://github.com/devture/com.devture.ansible.role.playbook_runtime_messages
- https://github.com/devture/com.devture.ansible.role.playbook_help

We just need to migrate to those.

roles/custom/matrix-backup-borg/templates/systemd/matrix-backup-borg.service.j2

@@ -0,0 +1,58 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=Matrix Borg Backup
+{% for service in matrix_backup_borg_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_backup_borg_systemd_wanted_services_list %}
+Wants={{ service }}
+{% endfor %}
+DefaultDependencies=no
+
+[Service]
+Type=oneshot
+Environment="HOME={{ matrix_systemd_unit_home_path }}"
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-backup-borg 2>/dev/null || true'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-backup-borg 2>/dev/null || true'
+ExecStartPre=-{{ matrix_host_command_docker }} run --rm --name matrix-backup-borg \
+			--log-driver=none \
+			--cap-drop=ALL \
+			--read-only \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--network={{ matrix_docker_network }} \
+			--tmpfs=/tmp:rw,noexec,nosuid,size=100m \
+			--mount type=bind,src={{ matrix_backup_borg_config_path }}/passwd,dst=/etc/passwd,ro \
+			--mount type=bind,src={{ matrix_backup_borg_config_path }},dst=/etc/borgmatic.d,ro \
+			{% for source in matrix_backup_borg_location_source_directories %}
+			--mount type=bind,src={{ source }},dst={{ source }},ro \
+			{% endfor %}
+			{% for arg in matrix_backup_borg_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			{{ matrix_backup_borg_docker_image }} \
+			sh -c "borgmatic --init --encryption {{ matrix_backup_borg_encryption }}"
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-backup-borg \
+			--log-driver=none \
+			--cap-drop=ALL \
+			--read-only \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--network={{ matrix_docker_network }} \
+			--tmpfs=/tmp:rw,noexec,nosuid,size=100m \
+			--mount type=bind,src={{ matrix_backup_borg_config_path }}/passwd,dst=/etc/passwd,ro \
+			--mount type=bind,src={{ matrix_backup_borg_config_path }},dst=/etc/borgmatic.d,ro \
+			{% for source in matrix_backup_borg_location_source_directories %}
+			--mount type=bind,src={{ source }},dst={{ source }},ro \
+			{% endfor %}
+			{% for arg in matrix_backup_borg_container_extra_arguments %}
+			{{ arg }} \
+			{% endfor %}
+			{{ matrix_backup_borg_docker_image }}
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-backup-borg 2>/dev/null || true'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-backup-borg 2>/dev/null || true'
+SyslogIdentifier=matrix-backup-borg
+
+[Install]
+WantedBy=multi-user.target

roles/custom/matrix-backup-borg/templates/systemd/matrix-backup-borg.timer.j2

@@ -0,0 +1,10 @@
+[Unit]
+Description=Matrix Borg Backup timer
+
+[Timer]
+Unit=matrix-backup-borg.service
+OnCalendar={{ matrix_backup_borg_schedule }}
+RandomizedDelaySec={{ matrix_backup_borg_schedule_randomized_delay_sec }}
+
+[Install]
+WantedBy=timers.target