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-cactus-comments/templates/cactus_appservice.yaml.j2

@@ -0,0 +1,19 @@
+# A unique, user-defined ID of the application service which will never change.
+id: "Cactus Comments"
+
+# Where the cactus-appservice is hosted:
+url: "http://matrix-cactus-comments:{{ matrix_cactus_comments_container_port }}"
+
+# Unique tokens used to authenticate requests between our service and the
+# homeserver (and the other way). Use the sha256 hashes of something random.
+# CHANGE THESE VALUES.
+as_token: {{ matrix_cactus_comments_as_token | to_json }}
+hs_token: {{ matrix_cactus_comments_hs_token | to_json }}
+
+# The user id of the cactusbot which can be used to register and moderate sites
+sender_localpart: "{{ matrix_cactus_comments_user_id }}"
+
+namespaces:
+  aliases:
+    - exclusive: true
+      regex: "#comments_.*"

roles/custom/matrix-cactus-comments/templates/env.j2

@@ -0,0 +1,6 @@
+CACTUS_HS_TOKEN={{ matrix_cactus_comments_hs_token }}
+CACTUS_AS_TOKEN={{ matrix_cactus_comments_as_token }}
+CACTUS_HOMESERVER_URL={{ matrix_cactus_comments_homeserver_url }}
+CACTUS_USER_ID=@{{ matrix_cactus_comments_user_id }}:{{ matrix_domain }}
+
+{{ matrix_cactus_comments_environment_variables_extension }}

roles/custom/matrix-cactus-comments/templates/systemd/matrix-cactus-comments.service.j2

@@ -0,0 +1,36 @@
+#jinja2: lstrip_blocks: "True"
+[Unit]
+Description=Cactus Comments
+{% for service in matrix_bot_cactus_comments_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_bot_cactus_comments_systemd_wanted_services_list %}
+Wants={{ service }}
+{% endfor %}
+DefaultDependencies=no
+
+[Service]
+Type=simple
+Environment="HOME={{ matrix_systemd_unit_home_path }}"
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-cactus-comments 2>/dev/null || true'
+ExecStartPre=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-cactus-comments 2>/dev/null || true'
+
+ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-cactus-comments \
+			--log-driver=none \
+			--cap-drop=ALL \
+			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
+			--read-only \
+			--env-file {{ matrix_cactus_comments_app_service_env_file }} \
+			--tmpfs=/tmp:rw,noexec,nosuid,size={{ matrix_cactus_comments_tmp_directory_size_mb }}m \
+			--network={{ matrix_docker_network }} \
+			{{ matrix_cactus_comments_docker_image }}
+
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} kill matrix-cactus-comments 2>/dev/null || true'
+ExecStop=-{{ matrix_host_command_sh }} -c '{{ matrix_host_command_docker }} rm matrix-cactus-comments 2>/dev/null || true'
+Restart=always
+RestartSec=30
+SyslogIdentifier=matrix-cactus-comments
+
+[Install]
+WantedBy=multi-user.target